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routing: simplify decompose_change_notification().

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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
This commit is contained in:
Alexander V. Chernikov 2022-06-27 17:29:03 +00:00
parent 76f1ab8eff
commit 8010b7a78a
1 changed files with 61 additions and 67 deletions
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128
sys/net/route/route_helpers.c
View File

@ -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: