git: 8010b7a78a3a - main - routing: simplify decompose_change_notification().
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Date: Mon, 27 Jun 2022 17:32:54 UTC
The branch main has been updated by melifaro:
URL: https://cgit.FreeBSD.org/src/commit/?id=8010b7a78a3af66dda1c74373499794af9ffd35f
commit 8010b7a78a3af66dda1c74373499794af9ffd35f
Author: Alexander V. Chernikov <melifaro@FreeBSD.org>
AuthorDate: 2022-06-27 17:29:03 +0000
Commit: Alexander V. Chernikov <melifaro@FreeBSD.org>
CommitDate: 2022-06-27 17:30:52 +0000
routing: simplify decompose_change_notification().
The function's goal is to compare old/new nhop/nexthop group for the route
and decompose it into the series of RTM_ADD/RTM_DELETE single-nhop
events, calling specified callback for each event.
Simplify it by properly leveraging the fact that both old/new groups
are sorted nhop-# ascending.
Tested by: Claudio Jeker<claudio.jeker@klarasystems.com>
Differential Revision: https://reviews.freebsd.org/D35598
MFC after: 2 weeks
---
sys/net/route/route_helpers.c | 128 ++++++++++++++++++++----------------------
1 file changed, 61 insertions(+), 67 deletions(-)
diff --git a/sys/net/route/route_helpers.c b/sys/net/route/route_helpers.c
index 0696eec416b1..1577df5513d3 100644
--- a/sys/net/route/route_helpers.c
+++ b/sys/net/route/route_helpers.c
@@ -64,6 +64,11 @@ __FBSDID("$FreeBSD$");
#endif
#include <net/vnet.h>
+#define DEBUG_MOD_NAME rt_helpers
+#define DEBUG_MAX_LEVEL LOG_DEBUG2
+#include <net/route/route_debug.h>
+_DECLARE_DEBUG(LOG_INFO);
+
/*
* RIB helper functions.
*/
@@ -253,13 +258,38 @@ rib_lookup(uint32_t fibnum, const struct sockaddr *dst, uint32_t flags,
return (nh);
}
+static void
+notify_add(struct rib_cmd_info *rc, const struct weightened_nhop *wn_src,
+ route_notification_t *cb, void *cbdata) {
+ rc->rc_nh_new = wn_src->nh;
+ rc->rc_nh_weight = wn_src->weight;
+#if DEBUG_MAX_LEVEL >= LOG_DEBUG2
+ char nhbuf[NHOP_PRINT_BUFSIZE];
+ FIB_NH_LOG(LOG_DEBUG2, wn_src->nh, "RTM_ADD for %s @ w=%u",
+ nhop_print_buf(wn_src->nh, nhbuf, sizeof(nhbuf)), wn_src->weight);
+#endif
+ cb(rc, cbdata);
+}
+
+static void
+notify_del(struct rib_cmd_info *rc, const struct weightened_nhop *wn_src,
+ route_notification_t *cb, void *cbdata) {
+ rc->rc_nh_old = wn_src->nh;
+ rc->rc_nh_weight = wn_src->weight;
+#if DEBUG_MAX_LEVEL >= LOG_DEBUG2
+ char nhbuf[NHOP_PRINT_BUFSIZE];
+ FIB_NH_LOG(LOG_DEBUG2, wn_src->nh, "RTM_DEL for %s @ w=%u",
+ nhop_print_buf(wn_src->nh, nhbuf, sizeof(nhbuf)), wn_src->weight);
+#endif
+ cb(rc, cbdata);
+}
+
#ifdef ROUTE_MPATH
static void
decompose_change_notification(struct rib_cmd_info *rc, route_notification_t *cb,
void *cbdata)
{
uint32_t num_old, num_new;
- uint32_t nh_idx_old, nh_idx_new;
struct weightened_nhop *wn_old, *wn_new;
struct weightened_nhop tmp = { NULL, 0 };
uint32_t idx_old = 0, idx_new = 0;
@@ -283,90 +313,58 @@ decompose_change_notification(struct rib_cmd_info *rc, route_notification_t *cb,
wn_new = &tmp;
num_new = 1;
}
+#if DEBUG_MAX_LEVEL >= LOG_DEBUG
+ {
+ char buf_old[NHOP_PRINT_BUFSIZE], buf_new[NHOP_PRINT_BUFSIZE];
+ nhop_print_buf_any(rc->rc_nh_old, buf_old, NHOP_PRINT_BUFSIZE);
+ nhop_print_buf_any(rc->rc_nh_new, buf_new, NHOP_PRINT_BUFSIZE);
+ FIB_NH_LOG(LOG_DEBUG, wn_old[0].nh, "change %s -> %s", buf_old, buf_new);
+ }
+#endif
/* Use the fact that each @wn array is sorted */
/*
- * Want to convert into set of add and delete operations
- * [1] -> [1, 2] = A{2}
- * [2] -> [1, 2] = A{1}
- * [1, 2, 4]->[1, 3, 4] = A{2}, D{3}
- * [1, 2, 4]->[1, 4] = D{2}
- * [1, 2, 4] -> [3, 4] = D{1}, C{2,3} OR C{1,3}, D{2} OR D{1},D{2},A{3}
- * [1, 2] -> [3, 4] =
+ * Here we have one (or two) multipath groups and transition
+ * between them needs to be reported to the caller, using series
+ * of primitive (RTM_DEL, RTM_ADD) operations.
*
+ * Leverage the fact that each nexthop group has its nexthops sorted
+ * by their indices.
+ * [1] -> [1, 2] = A{2}
+ * [1, 2] -> [1] = D{2}
+ * [1, 2, 4] -> [1, 3, 4] = D{2}, A{3}
+ * [1, 2] -> [3, 4] = D{1}, D{2}, A{3}, A{4]
*/
- idx_old = 0;
while ((idx_old < num_old) && (idx_new < num_new)) {
- nh_idx_old = wn_old[idx_old].nh->nh_priv->nh_idx;
- nh_idx_new = wn_new[idx_new].nh->nh_priv->nh_idx;
+ uint32_t nh_idx_old = wn_old[idx_old].nh->nh_priv->nh_idx;
+ uint32_t nh_idx_new = wn_new[idx_new].nh->nh_priv->nh_idx;
if (nh_idx_old == nh_idx_new) {
if (wn_old[idx_old].weight != wn_new[idx_new].weight) {
/* Update weight by providing del/add notifications */
- rc_del.rc_nh_old = wn_old[idx_old].nh;
- rc_del.rc_nh_weight = wn_old[idx_old].weight;
- cb(&rc_del, cbdata);
-
- rc_add.rc_nh_new = wn_new[idx_new].nh;
- rc_add.rc_nh_weight = wn_new[idx_new].weight;
- cb(&rc_add, cbdata);
+ notify_del(&rc_del, &wn_old[idx_old], cb, cbdata);
+ notify_add(&rc_add, &wn_new[idx_new], cb, cbdata);
}
idx_old++;
idx_new++;
} else if (nh_idx_old < nh_idx_new) {
- /*
- * [1, ~2~, 4], [1, ~3~, 4]
- * [1, ~2~, 5], [1, ~3~, 4]
- * [1, ~2~], [1, ~3~, 4]
- */
- if ((idx_old + 1 >= num_old) ||
- (wn_old[idx_old + 1].nh->nh_priv->nh_idx > nh_idx_new)) {
- /* Add new unless the next old item is still <= new */
- rc_add.rc_nh_new = wn_new[idx_new].nh;
- rc_add.rc_nh_weight = wn_new[idx_new].weight;
- cb(&rc_add, cbdata);
- idx_new++;
- }
- /* In any case, delete current old */
- rc_del.rc_nh_old = wn_old[idx_old].nh;
- rc_del.rc_nh_weight = wn_old[idx_old].weight;
- cb(&rc_del, cbdata);
+ /* [1, ~2~, 4], [1, ~3~, 4] */
+ notify_del(&rc_del, &wn_old[idx_old], cb, cbdata);
idx_old++;
} else {
- /*
- * nh_idx_old > nh_idx_new
- *
- * [1, ~3~, 4], [1, ~2~, 4]
- * [1, ~3~, 5], [1, ~2~, 4]
- * [1, ~3~, 4], [1, ~2~]
- */
- if ((idx_new + 1 >= num_new) ||
- (wn_new[idx_new + 1].nh->nh_priv->nh_idx > nh_idx_old)) {
- /* No next item or next item is > current one */
- rc_add.rc_nh_new = wn_new[idx_new].nh;
- rc_add.rc_nh_weight = wn_new[idx_new].weight;
- cb(&rc_add, cbdata);
- idx_new++;
- }
- /* In any case, delete current old */
- rc_del.rc_nh_old = wn_old[idx_old].nh;
- rc_del.rc_nh_weight = wn_old[idx_old].weight;
- cb(&rc_del, cbdata);
- idx_old++;
+ /* nh_idx_old > nh_idx_new. */
+ notify_add(&rc_add, &wn_new[idx_new], cb, cbdata);
+ idx_new++;
}
}
while (idx_old < num_old) {
- rc_del.rc_nh_old = wn_old[idx_old].nh;
- rc_del.rc_nh_weight = wn_old[idx_old].weight;
- cb(&rc_del, cbdata);
+ notify_del(&rc_del, &wn_old[idx_old], cb, cbdata);
idx_old++;
}
while (idx_new < num_new) {
- rc_add.rc_nh_new = wn_new[idx_new].nh;
- rc_add.rc_nh_weight = wn_new[idx_new].weight;
- cb(&rc_add, cbdata);
+ notify_add(&rc_add, &wn_new[idx_new], cb, cbdata);
idx_new++;
}
}
@@ -393,9 +391,7 @@ rib_decompose_notification(struct rib_cmd_info *rc, route_notification_t *cb,
return;
wn = nhgrp_get_nhops((struct nhgrp_object *)rc->rc_nh_new, &num_nhops);
for (uint32_t i = 0; i < num_nhops; i++) {
- rc_new.rc_nh_new = wn[i].nh;
- rc_new.rc_nh_weight = wn[i].weight;
- cb(&rc_new, cbdata);
+ notify_add(&rc_new, &wn[i], cb, cbdata);
}
break;
case RTM_DELETE:
@@ -403,9 +399,7 @@ rib_decompose_notification(struct rib_cmd_info *rc, route_notification_t *cb,
return;
wn = nhgrp_get_nhops((struct nhgrp_object *)rc->rc_nh_old, &num_nhops);
for (uint32_t i = 0; i < num_nhops; i++) {
- rc_new.rc_nh_old = wn[i].nh;
- rc_new.rc_nh_weight = wn[i].weight;
- cb(&rc_new, cbdata);
+ notify_del(&rc_new, &wn[i], cb, cbdata);
}
break;
case RTM_CHANGE: