git: ede90c997743 - stable/13 - routing: fix RTM_CHANGE nhgroup updates.

The branch stable/13 has been updated by melifaro:

URL: https://cgit.FreeBSD.org/src/commit/?id=ede90c99774338479be58e88e9bce800f54bf12b

commit ede90c99774338479be58e88e9bce800f54bf12b
Author:     Alexander V. Chernikov <melifaro@FreeBSD.org>
AuthorDate: 2022-06-25 18:54:37 +0000
Commit:     Alexander V. Chernikov <melifaro@FreeBSD.org>
CommitDate: 2023-01-13 21:18:25 +0000

    routing: fix RTM_CHANGE nhgroup updates.
    
    RTM_CHANGE operates on a single component of the multipath route (e.g. on a single nexthop).
    Search of this nexthop is peformed by iterating over each component from multipath (nexthop)
     group, using check_info_match_nhop. The problem with the current code that it incorrectly
     assumes that `check_info_match_nhop()` returns true value on match, while in reality it
     returns an error code on failure). Fix this by properly comparing the result with 0.
    Additionally, the followup code modified original necthop group instead of a new one.
    Fix this by targetting new nexthop group instead.
    
    Reported by:    thj
    Tested by:      Claudio Jeker <claudio.jeker@klarasystems.com>
    Differential Revision: https://reviews.freebsd.org/D35526
    MFC after: 2 weeks
    
    (cherry picked from commit c38da70c28a886cc31a2f009baa79deb7fceec88)
---
 sys/net/route/route_ctl.c | 34 +++++++++++++++++++++-------------
 1 file changed, 21 insertions(+), 13 deletions(-)

diff --git a/sys/net/route/route_ctl.c b/sys/net/route/route_ctl.c
index afe0a024b832..8a61db449462 100644
--- a/sys/net/route/route_ctl.c
+++ b/sys/net/route/route_ctl.c
@@ -57,6 +57,11 @@ __FBSDID("$FreeBSD$");
 
 #include <vm/uma.h>
 
+#define	DEBUG_MOD_NAME	route_ctl
+#define	DEBUG_MAX_LEVEL	LOG_DEBUG
+#include <net/route/route_debug.h>
+_DECLARE_DEBUG(LOG_INFO);
+
 /*
  * This file contains control plane routing tables functions.
  *
@@ -999,18 +1004,17 @@ static int
 change_mpath_route(struct rib_head *rnh, struct rt_addrinfo *info,
     struct route_nhop_data *rnd_orig, struct rib_cmd_info *rc)
 {
-	int error = 0;
-	struct nhop_object *nh_orig, *nh_new;
+	int error = 0, found_idx = 0;
+	struct nhop_object *nh_orig = NULL, *nh_new;
 	struct route_nhop_data rnd_new;
 	struct weightened_nhop *wn = NULL, *wn_new;
 	uint32_t num_nhops;
 
-	nh_orig = rnd_orig->rnd_nhop;
-	wn = nhgrp_get_nhops((struct nhgrp_object *)nh_orig, &num_nhops);
-	nh_orig = NULL;
+	wn = nhgrp_get_nhops(rnd_orig->rnd_nhgrp, &num_nhops);
 	for (int i = 0; i < num_nhops; i++) {
-		if (check_info_match_nhop(info, NULL, wn[i].nh)) {
+		if (check_info_match_nhop(info, NULL, wn[i].nh) == 0) {
 			nh_orig = wn[i].nh;
+			found_idx = i;
 			break;
 		}
 	}
@@ -1030,13 +1034,8 @@ change_mpath_route(struct rib_head *rnh, struct rt_addrinfo *info,
 	}
 
 	memcpy(wn_new, wn, num_nhops * sizeof(struct weightened_nhop));
-	for (int i = 0; i < num_nhops; i++) {
-		if (wn[i].nh == nh_orig) {
-			wn[i].nh = nh_new;
-			wn[i].weight = get_info_weight(info, rnd_orig->rnd_weight);
-			break;
-		}
-	}
+	wn_new[found_idx].nh = nh_new;
+	wn_new[found_idx].weight = get_info_weight(info, wn[found_idx].weight);
 
 	error = nhgrp_get_group(rnh, wn_new, num_nhops, &rnd_new);
 	nhop_free(nh_new);
@@ -1188,6 +1187,15 @@ change_route_conditional(struct rib_head *rnh, struct rtentry *rt,
 	struct rtentry *rt_new;
 	int error = 0;
 
+#if DEBUG_MAX_LEVEL >= LOG_DEBUG2
+	{
+		char buf_old[NHOP_PRINT_BUFSIZE], buf_new[NHOP_PRINT_BUFSIZE];
+		nhop_print_buf_any(rnd_orig->rnd_nhop, buf_old, NHOP_PRINT_BUFSIZE);
+		nhop_print_buf_any(rnd_new->rnd_nhop, buf_new, NHOP_PRINT_BUFSIZE);
+		FIB_LOG(LOG_DEBUG2, rnh->rib_fibnum, rnh->rib_family,
+		    "trying change %s -> %s", buf_old, buf_new);
+	}
+#endif
 	RIB_WLOCK(rnh);
 
 	rt_new = (struct rtentry *)rnh->rnh_lookup(info->rti_info[RTAX_DST],