Linux kernel mirror (for testing)
git.kernel.org/pub/scm/linux/kernel/git/torvalds/linux.git
kernel
os
linux
ipv6: Factorise ip6_route_multipath_add().
We will get rid of RTNL from RTM_NEWROUTE and SIOCADDRT and rely
on RCU to guarantee dev and nexthop lifetime.
Then, the RCU section will start before ip6_route_info_create_nh()
in ip6_route_multipath_add(), but ip6_route_info_create() is called
in the same loop and will sleep.
Let's split the loop into ip6_route_mpath_info_create() and
ip6_route_mpath_info_create_nh().
Note that ip6_route_info_append() is now integrated into
ip6_route_mpath_info_create_nh() because we need to call different
free functions for nexthops that passed ip6_route_info_create_nh().
In case of failure, the remaining nexthops that ip6_route_info_create_nh()
has not been called for will be freed by ip6_route_mpath_info_cleanup().
OTOH, if a nexthop passes ip6_route_info_create_nh(), it will be linked
to a local temporary list, which will be spliced back to rt6_nh_list.
In case of failure, these nexthops will be released by fib6_info_release()
in ip6_route_multipath_add().
Signed-off-by: Kuniyuki Iwashima <kuniyu@amazon.com>
Link: https://patch.msgid.link/20250418000443.43734-12-kuniyu@amazon.com
Signed-off-by: Paolo Abeni <pabeni@redhat.com>
authored by
Kuniyuki Iwashima
and committed by
Paolo Abeni
71c0efb6
5a1ccff5
+132
-77
+132
-77
net/ipv6/route.c
+132
-77
net/ipv6/route.c
···
5316
5316
struct fib6_info *fib6_info;
5317
5317
struct fib6_config r_cfg;
5318
5318
struct list_head list;
5319
+
int weight;
5319
5320
};
5320
5321
5321
-
static int ip6_route_info_append(struct list_head *rt6_nh_list,
5322
-
struct fib6_info *rt,
5323
-
struct fib6_config *r_cfg)
5322
+
static void ip6_route_mpath_info_cleanup(struct list_head *rt6_nh_list)
5324
5323
{
5325
-
struct rt6_nh *nh;
5326
-
int err = -EEXIST;
5324
+
struct rt6_nh *nh, *nh_next;
5327
5325
5328
-
list_for_each_entry(nh, rt6_nh_list, list) {
5329
-
/* check if fib6_info already exists */
5330
-
if (rt6_duplicate_nexthop(nh->fib6_info, rt))
5331
-
return err;
5326
+
list_for_each_entry_safe(nh, nh_next, rt6_nh_list, list) {
5327
+
struct fib6_info *rt = nh->fib6_info;
5328
+
5329
+
if (rt) {
5330
+
free_percpu(rt->fib6_nh->nh_common.nhc_pcpu_rth_output);
5331
+
free_percpu(rt->fib6_nh->rt6i_pcpu);
5332
+
ip_fib_metrics_put(rt->fib6_metrics);
5333
+
kfree(rt);
5334
+
}
5335
+
5336
+
list_del(&nh->list);
5337
+
kfree(nh);
5338
+
}
5339
+
}
5340
+
5341
+
static int ip6_route_mpath_info_create(struct list_head *rt6_nh_list,
5342
+
struct fib6_config *cfg,
5343
+
struct netlink_ext_ack *extack)
5344
+
{
5345
+
struct rtnexthop *rtnh;
5346
+
int remaining;
5347
+
int err;
5348
+
5349
+
remaining = cfg->fc_mp_len;
5350
+
rtnh = (struct rtnexthop *)cfg->fc_mp;
5351
+
5352
+
/* Parse a Multipath Entry and build a list (rt6_nh_list) of
5353
+
* fib6_info structs per nexthop
5354
+
*/
5355
+
while (rtnh_ok(rtnh, remaining)) {
5356
+
struct fib6_config r_cfg;
5357
+
struct fib6_info *rt;
5358
+
struct rt6_nh *nh;
5359
+
int attrlen;
5360
+
5361
+
nh = kzalloc(sizeof(*nh), GFP_KERNEL);
5362
+
if (!nh) {
5363
+
err = -ENOMEM;
5364
+
goto err;
5365
+
}
5366
+
5367
+
list_add_tail(&nh->list, rt6_nh_list);
5368
+
5369
+
memcpy(&r_cfg, cfg, sizeof(*cfg));
5370
+
if (rtnh->rtnh_ifindex)
5371
+
r_cfg.fc_ifindex = rtnh->rtnh_ifindex;
5372
+
5373
+
attrlen = rtnh_attrlen(rtnh);
5374
+
if (attrlen > 0) {
5375
+
struct nlattr *nla, *attrs = rtnh_attrs(rtnh);
5376
+
5377
+
nla = nla_find(attrs, attrlen, RTA_GATEWAY);
5378
+
if (nla) {
5379
+
r_cfg.fc_gateway = nla_get_in6_addr(nla);
5380
+
r_cfg.fc_flags |= RTF_GATEWAY;
5381
+
}
5382
+
5383
+
r_cfg.fc_encap = nla_find(attrs, attrlen, RTA_ENCAP);
5384
+
nla = nla_find(attrs, attrlen, RTA_ENCAP_TYPE);
5385
+
if (nla)
5386
+
r_cfg.fc_encap_type = nla_get_u16(nla);
5387
+
}
5388
+
5389
+
r_cfg.fc_flags |= (rtnh->rtnh_flags & RTNH_F_ONLINK);
5390
+
5391
+
rt = ip6_route_info_create(&r_cfg, GFP_KERNEL, extack);
5392
+
if (IS_ERR(rt)) {
5393
+
err = PTR_ERR(rt);
5394
+
goto err;
5395
+
}
5396
+
5397
+
nh->fib6_info = rt;
5398
+
nh->weight = rtnh->rtnh_hops + 1;
5399
+
memcpy(&nh->r_cfg, &r_cfg, sizeof(r_cfg));
5400
+
5401
+
rtnh = rtnh_next(rtnh, &remaining);
5332
5402
}
5333
5403
5334
-
nh = kzalloc(sizeof(*nh), GFP_KERNEL);
5335
-
if (!nh)
5336
-
return -ENOMEM;
5337
-
nh->fib6_info = rt;
5338
-
memcpy(&nh->r_cfg, r_cfg, sizeof(*r_cfg));
5339
-
list_add_tail(&nh->list, rt6_nh_list);
5340
-
5341
5404
return 0;
5405
+
err:
5406
+
ip6_route_mpath_info_cleanup(rt6_nh_list);
5407
+
return err;
5408
+
}
5409
+
5410
+
static int ip6_route_mpath_info_create_nh(struct list_head *rt6_nh_list,
5411
+
struct netlink_ext_ack *extack)
5412
+
{
5413
+
struct rt6_nh *nh, *nh_next, *nh_tmp;
5414
+
LIST_HEAD(tmp);
5415
+
int err;
5416
+
5417
+
list_for_each_entry_safe(nh, nh_next, rt6_nh_list, list) {
5418
+
struct fib6_info *rt = nh->fib6_info;
5419
+
5420
+
err = ip6_route_info_create_nh(rt, &nh->r_cfg, extack);
5421
+
if (err) {
5422
+
nh->fib6_info = NULL;
5423
+
goto err;
5424
+
}
5425
+
5426
+
rt->fib6_nh->fib_nh_weight = nh->weight;
5427
+
5428
+
list_move_tail(&nh->list, &tmp);
5429
+
5430
+
list_for_each_entry(nh_tmp, rt6_nh_list, list) {
5431
+
/* check if fib6_info already exists */
5432
+
if (rt6_duplicate_nexthop(nh_tmp->fib6_info, rt)) {
5433
+
err = -EEXIST;
5434
+
goto err;
5435
+
}
5436
+
}
5437
+
}
5438
+
out:
5439
+
list_splice(&tmp, rt6_nh_list);
5440
+
return err;
5441
+
err:
5442
+
ip6_route_mpath_info_cleanup(rt6_nh_list);
5443
+
goto out;
5342
5444
}
5343
5445
5344
5446
static void ip6_route_mpath_notify(struct fib6_info *rt,
···
5499
5397
{
5500
5398
struct fib6_info *rt_notif = NULL, *rt_last = NULL;
5501
5399
struct nl_info *info = &cfg->fc_nlinfo;
5502
-
struct fib6_config r_cfg;
5503
-
struct rtnexthop *rtnh;
5504
-
struct fib6_info *rt;
5505
-
struct rt6_nh *err_nh;
5506
5400
struct rt6_nh *nh, *nh_safe;
5507
-
__u16 nlflags;
5508
-
int remaining;
5509
-
int attrlen;
5510
-
int err = 1;
5511
-
int nhn = 0;
5512
-
int replace = (cfg->fc_nlinfo.nlh &&
5513
-
(cfg->fc_nlinfo.nlh->nlmsg_flags & NLM_F_REPLACE));
5514
5401
LIST_HEAD(rt6_nh_list);
5402
+
struct rt6_nh *err_nh;
5403
+
__u16 nlflags;
5404
+
int nhn = 0;
5405
+
int replace;
5406
+
int err;
5407
+
5408
+
replace = (cfg->fc_nlinfo.nlh &&
5409
+
(cfg->fc_nlinfo.nlh->nlmsg_flags & NLM_F_REPLACE));
5515
5410
5516
5411
nlflags = replace ? NLM_F_REPLACE : NLM_F_CREATE;
5517
5412
if (info->nlh && info->nlh->nlmsg_flags & NLM_F_APPEND)
5518
5413
nlflags |= NLM_F_APPEND;
5519
5414
5520
-
remaining = cfg->fc_mp_len;
5521
-
rtnh = (struct rtnexthop *)cfg->fc_mp;
5415
+
err = ip6_route_mpath_info_create(&rt6_nh_list, cfg, extack);
5416
+
if (err)
5417
+
return err;
5522
5418
5523
-
/* Parse a Multipath Entry and build a list (rt6_nh_list) of
5524
-
* fib6_info structs per nexthop
5525
-
*/
5526
-
while (rtnh_ok(rtnh, remaining)) {
5527
-
memcpy(&r_cfg, cfg, sizeof(*cfg));
5528
-
if (rtnh->rtnh_ifindex)
5529
-
r_cfg.fc_ifindex = rtnh->rtnh_ifindex;
5530
-
5531
-
attrlen = rtnh_attrlen(rtnh);
5532
-
if (attrlen > 0) {
5533
-
struct nlattr *nla, *attrs = rtnh_attrs(rtnh);
5534
-
5535
-
nla = nla_find(attrs, attrlen, RTA_GATEWAY);
5536
-
if (nla) {
5537
-
r_cfg.fc_gateway = nla_get_in6_addr(nla);
5538
-
r_cfg.fc_flags |= RTF_GATEWAY;
5539
-
}
5540
-
5541
-
r_cfg.fc_encap = nla_find(attrs, attrlen, RTA_ENCAP);
5542
-
nla = nla_find(attrs, attrlen, RTA_ENCAP_TYPE);
5543
-
if (nla)
5544
-
r_cfg.fc_encap_type = nla_get_u16(nla);
5545
-
}
5546
-
5547
-
r_cfg.fc_flags |= (rtnh->rtnh_flags & RTNH_F_ONLINK);
5548
-
rt = ip6_route_info_create(&r_cfg, GFP_KERNEL, extack);
5549
-
if (IS_ERR(rt)) {
5550
-
err = PTR_ERR(rt);
5551
-
rt = NULL;
5552
-
goto cleanup;
5553
-
}
5554
-
5555
-
err = ip6_route_info_create_nh(rt, &r_cfg, extack);
5556
-
if (err) {
5557
-
rt = NULL;
5558
-
goto cleanup;
5559
-
}
5560
-
5561
-
rt->fib6_nh->fib_nh_weight = rtnh->rtnh_hops + 1;
5562
-
5563
-
err = ip6_route_info_append(&rt6_nh_list, rt, &r_cfg);
5564
-
if (err) {
5565
-
fib6_info_release(rt);
5566
-
goto cleanup;
5567
-
}
5568
-
5569
-
rtnh = rtnh_next(rtnh, &remaining);
5570
-
}
5419
+
err = ip6_route_mpath_info_create_nh(&rt6_nh_list, extack);
5420
+
if (err)
5421
+
goto cleanup;
5571
5422
5572
5423
/* for add and replace send one notification with all nexthops.
5573
5424
* Skip the notification in fib6_add_rt2node and send one with