This is a note to let you know that I've just added the patch titled
net: Add l3mdev index to flow struct and avoid oif reset for port devices
to the 5.15-stable tree which can be found at:
http://www.kernel.org/git/?p=linux/kernel/git/stable/stable-queue.git;a=summary
The filename of the patch is:
net-add-l3mdev-index-to-flow-struct-and-avoid-oif-re.patch
and it can be found in the queue-5.15 subdirectory.
If you, or anyone else, feels it should not be added to the stable tree,
please let <stable@xxxxxxxxxxxxxxx> know about it.
commit 16e9d306e5b7b1f72a5ad15fef79d17b4b72c9fd
Author: David Ahern <dsahern@xxxxxxxxxx>
Date: Mon Mar 14 14:45:51 2022 -0600
net: Add l3mdev index to flow struct and avoid oif reset for port devices
[ Upstream commit 40867d74c374b235e14d839f3a77f26684feefe5 ]
The fundamental premise of VRF and l3mdev core code is binding a socket
to a device (l3mdev or netdev with an L3 domain) to indicate L3 scope.
Legacy code resets flowi_oif to the l3mdev losing any original port
device binding. Ben (among others) has demonstrated use cases where the
original port device binding is important and needs to be retained.
This patch handles that by adding a new entry to the common flow struct
that can indicate the l3mdev index for later rule and table matching
avoiding the need to reset flowi_oif.
In addition to allowing more use cases that require port device binds,
this patch brings a few datapath simplications:
1. l3mdev_fib_rule_match is only called when walking fib rules and
always after l3mdev_update_flow. That allows an optimization to bail
early for non-VRF type uses cases when flowi_l3mdev is not set. Also,
only that index needs to be checked for the FIB table id.
2. l3mdev_update_flow can be called with flowi_oif set to a l3mdev
(e.g., VRF) device. By resetting flowi_oif only for this case the
FLOWI_FLAG_SKIP_NH_OIF flag is not longer needed and can be removed,
removing several checks in the datapath. The flowi_iif path can be
simplified to only be called if the it is not loopback (loopback can
not be assigned to an L3 domain) and the l3mdev index is not already
set.
3. Avoid another device lookup in the output path when the fib lookup
returns a reject failure.
Note: 2 functional tests for local traffic with reject fib rules are
updated to reflect the new direct failure at FIB lookup time for ping
rather than the failure on packet path. The current code fails like this:
HINT: Fails since address on vrf device is out of device scope
COMMAND: ip netns exec ns-A ping -c1 -w1 -I eth1 172.16.3.1
ping: Warning: source address might be selected on device other than: eth1
PING 172.16.3.1 (172.16.3.1) from 172.16.3.1 eth1: 56(84) bytes of data.
--- 172.16.3.1 ping statistics ---
1 packets transmitted, 0 received, 100% packet loss, time 0ms
where the test now directly fails:
HINT: Fails since address on vrf device is out of device scope
COMMAND: ip netns exec ns-A ping -c1 -w1 -I eth1 172.16.3.1
ping: connect: No route to host
Signed-off-by: David Ahern <dsahern@xxxxxxxxxx>
Tested-by: Ben Greear <greearb@xxxxxxxxxxxxxxx>
Link: https://lore.kernel.org/r/20220314204551.16369-1-dsahern@xxxxxxxxxx
Signed-off-by: Jakub Kicinski <kuba@xxxxxxxxxx>
Stable-dep-of: 680735235356 ("ipv4: fix source address selection with route leak")
Signed-off-by: Sasha Levin <sashal@xxxxxxxxxx>
diff --git a/drivers/net/vrf.c b/drivers/net/vrf.c
index 091dd7caf10cc..85f5d78ff9ac0 100644
--- a/drivers/net/vrf.c
+++ b/drivers/net/vrf.c
@@ -471,14 +471,13 @@ static netdev_tx_t vrf_process_v6_outbound(struct sk_buff *skb,
memset(&fl6, 0, sizeof(fl6));
/* needed to match OIF rule */
- fl6.flowi6_oif = dev->ifindex;
+ fl6.flowi6_l3mdev = dev->ifindex;
fl6.flowi6_iif = LOOPBACK_IFINDEX;
fl6.daddr = iph->daddr;
fl6.saddr = iph->saddr;
fl6.flowlabel = ip6_flowinfo(iph);
fl6.flowi6_mark = skb->mark;
fl6.flowi6_proto = iph->nexthdr;
- fl6.flowi6_flags = FLOWI_FLAG_SKIP_NH_OIF;
dst = ip6_dst_lookup_flow(net, NULL, &fl6, NULL);
if (IS_ERR(dst) || dst == dst_null)
@@ -550,10 +549,10 @@ static netdev_tx_t vrf_process_v4_outbound(struct sk_buff *skb,
memset(&fl4, 0, sizeof(fl4));
/* needed to match OIF rule */
- fl4.flowi4_oif = vrf_dev->ifindex;
+ fl4.flowi4_l3mdev = vrf_dev->ifindex;
fl4.flowi4_iif = LOOPBACK_IFINDEX;
fl4.flowi4_tos = RT_TOS(ip4h->tos);
- fl4.flowi4_flags = FLOWI_FLAG_ANYSRC | FLOWI_FLAG_SKIP_NH_OIF;
+ fl4.flowi4_flags = FLOWI_FLAG_ANYSRC;
fl4.flowi4_proto = ip4h->protocol;
fl4.daddr = ip4h->daddr;
fl4.saddr = ip4h->saddr;
diff --git a/include/net/flow.h b/include/net/flow.h
index 776bacc96242a..079cc493fe67d 100644
--- a/include/net/flow.h
+++ b/include/net/flow.h
@@ -29,6 +29,7 @@ struct flowi_tunnel {
struct flowi_common {
int flowic_oif;
int flowic_iif;
+ int flowic_l3mdev;
__u32 flowic_mark;
__u8 flowic_tos;
__u8 flowic_scope;
@@ -36,7 +37,6 @@ struct flowi_common {
__u8 flowic_flags;
#define FLOWI_FLAG_ANYSRC 0x01
#define FLOWI_FLAG_KNOWN_NH 0x02
-#define FLOWI_FLAG_SKIP_NH_OIF 0x04
__u32 flowic_secid;
kuid_t flowic_uid;
__u32 flowic_multipath_hash;
@@ -65,6 +65,7 @@ struct flowi4 {
struct flowi_common __fl_common;
#define flowi4_oif __fl_common.flowic_oif
#define flowi4_iif __fl_common.flowic_iif
+#define flowi4_l3mdev __fl_common.flowic_l3mdev
#define flowi4_mark __fl_common.flowic_mark
#define flowi4_tos __fl_common.flowic_tos
#define flowi4_scope __fl_common.flowic_scope
@@ -97,6 +98,7 @@ static inline void flowi4_init_output(struct flowi4 *fl4, int oif,
{
fl4->flowi4_oif = oif;
fl4->flowi4_iif = LOOPBACK_IFINDEX;
+ fl4->flowi4_l3mdev = 0;
fl4->flowi4_mark = mark;
fl4->flowi4_tos = tos;
fl4->flowi4_scope = scope;
@@ -127,6 +129,7 @@ struct flowi6 {
struct flowi_common __fl_common;
#define flowi6_oif __fl_common.flowic_oif
#define flowi6_iif __fl_common.flowic_iif
+#define flowi6_l3mdev __fl_common.flowic_l3mdev
#define flowi6_mark __fl_common.flowic_mark
#define flowi6_scope __fl_common.flowic_scope
#define flowi6_proto __fl_common.flowic_proto
@@ -156,6 +159,7 @@ struct flowi {
} u;
#define flowi_oif u.__fl_common.flowic_oif
#define flowi_iif u.__fl_common.flowic_iif
+#define flowi_l3mdev u.__fl_common.flowic_l3mdev
#define flowi_mark u.__fl_common.flowic_mark
#define flowi_tos u.__fl_common.flowic_tos
#define flowi_scope u.__fl_common.flowic_scope
diff --git a/net/ipv4/fib_frontend.c b/net/ipv4/fib_frontend.c
index c21d57f02c651..5a3af86ee417a 100644
--- a/net/ipv4/fib_frontend.c
+++ b/net/ipv4/fib_frontend.c
@@ -290,7 +290,7 @@ __be32 fib_compute_spec_dst(struct sk_buff *skb)
bool vmark = in_dev && IN_DEV_SRC_VMARK(in_dev);
struct flowi4 fl4 = {
.flowi4_iif = LOOPBACK_IFINDEX,
- .flowi4_oif = l3mdev_master_ifindex_rcu(dev),
+ .flowi4_l3mdev = l3mdev_master_ifindex_rcu(dev),
.daddr = ip_hdr(skb)->saddr,
.flowi4_tos = ip_hdr(skb)->tos & IPTOS_RT_MASK,
.flowi4_scope = scope,
@@ -352,9 +352,8 @@ static int __fib_validate_source(struct sk_buff *skb, __be32 src, __be32 dst,
bool dev_match;
fl4.flowi4_oif = 0;
- fl4.flowi4_iif = l3mdev_master_ifindex_rcu(dev);
- if (!fl4.flowi4_iif)
- fl4.flowi4_iif = oif ? : LOOPBACK_IFINDEX;
+ fl4.flowi4_l3mdev = l3mdev_master_ifindex_rcu(dev);
+ fl4.flowi4_iif = oif ? : LOOPBACK_IFINDEX;
fl4.daddr = src;
fl4.saddr = dst;
fl4.flowi4_tos = tos;
diff --git a/net/ipv4/fib_semantics.c b/net/ipv4/fib_semantics.c
index 735901b8c9f69..3d00253afbb8d 100644
--- a/net/ipv4/fib_semantics.c
+++ b/net/ipv4/fib_semantics.c
@@ -2269,7 +2269,7 @@ void fib_select_multipath(struct fib_result *res, int hash)
void fib_select_path(struct net *net, struct fib_result *res,
struct flowi4 *fl4, const struct sk_buff *skb)
{
- if (fl4->flowi4_oif && !(fl4->flowi4_flags & FLOWI_FLAG_SKIP_NH_OIF))
+ if (fl4->flowi4_oif)
goto check_saddr;
#ifdef CONFIG_IP_ROUTE_MULTIPATH
diff --git a/net/ipv4/fib_trie.c b/net/ipv4/fib_trie.c
index 0b74debeecbb1..ec0113ecf3949 100644
--- a/net/ipv4/fib_trie.c
+++ b/net/ipv4/fib_trie.c
@@ -1428,11 +1428,8 @@ bool fib_lookup_good_nhc(const struct fib_nh_common *nhc, int fib_flags,
!(fib_flags & FIB_LOOKUP_IGNORE_LINKSTATE))
return false;
- if (!(flp->flowi4_flags & FLOWI_FLAG_SKIP_NH_OIF)) {
- if (flp->flowi4_oif &&
- flp->flowi4_oif != nhc->nhc_oif)
- return false;
- }
+ if (flp->flowi4_oif && flp->flowi4_oif != nhc->nhc_oif)
+ return false;
return true;
}
diff --git a/net/ipv4/route.c b/net/ipv4/route.c
index 60fc35defdf8b..3522801885787 100644
--- a/net/ipv4/route.c
+++ b/net/ipv4/route.c
@@ -2285,6 +2285,7 @@ static int ip_route_input_slow(struct sk_buff *skb, __be32 daddr, __be32 saddr,
/*
* Now we are ready to route packet.
*/
+ fl4.flowi4_l3mdev = 0;
fl4.flowi4_oif = 0;
fl4.flowi4_iif = dev->ifindex;
fl4.flowi4_mark = skb->mark;
@@ -2761,8 +2762,7 @@ struct rtable *ip_route_output_key_hash_rcu(struct net *net, struct flowi4 *fl4,
res->fi = NULL;
res->table = NULL;
if (fl4->flowi4_oif &&
- (ipv4_is_multicast(fl4->daddr) ||
- !netif_index_is_l3_master(net, fl4->flowi4_oif))) {
+ (ipv4_is_multicast(fl4->daddr) || !fl4->flowi4_l3mdev)) {
/* Apparently, routing tables are wrong. Assume,
* that the destination is on link.
*
diff --git a/net/ipv4/xfrm4_policy.c b/net/ipv4/xfrm4_policy.c
index 9ebd54752e03b..4548a91acdc89 100644
--- a/net/ipv4/xfrm4_policy.c
+++ b/net/ipv4/xfrm4_policy.c
@@ -28,13 +28,11 @@ static struct dst_entry *__xfrm4_dst_lookup(struct net *net, struct flowi4 *fl4,
memset(fl4, 0, sizeof(*fl4));
fl4->daddr = daddr->a4;
fl4->flowi4_tos = tos;
- fl4->flowi4_oif = l3mdev_master_ifindex_by_index(net, oif);
+ fl4->flowi4_l3mdev = l3mdev_master_ifindex_by_index(net, oif);
fl4->flowi4_mark = mark;
if (saddr)
fl4->saddr = saddr->a4;
- fl4->flowi4_flags = FLOWI_FLAG_SKIP_NH_OIF;
-
rt = __ip_route_output_key(net, fl4);
if (!IS_ERR(rt))
return &rt->dst;
diff --git a/net/ipv6/ip6_output.c b/net/ipv6/ip6_output.c
index ce37c83455796..afcc3c44d87cf 100644
--- a/net/ipv6/ip6_output.c
+++ b/net/ipv6/ip6_output.c
@@ -1058,8 +1058,7 @@ static struct dst_entry *ip6_sk_dst_check(struct sock *sk,
#ifdef CONFIG_IPV6_SUBTREES
ip6_rt_check(&rt->rt6i_src, &fl6->saddr, np->saddr_cache) ||
#endif
- (!(fl6->flowi6_flags & FLOWI_FLAG_SKIP_NH_OIF) &&
- (fl6->flowi6_oif && fl6->flowi6_oif != dst->dev->ifindex))) {
+ (fl6->flowi6_oif && fl6->flowi6_oif != dst->dev->ifindex)) {
dst_release(dst);
dst = NULL;
}
diff --git a/net/ipv6/route.c b/net/ipv6/route.c
index d937ee942a4fc..35d3f02ddf163 100644
--- a/net/ipv6/route.c
+++ b/net/ipv6/route.c
@@ -1209,9 +1209,6 @@ INDIRECT_CALLABLE_SCOPE struct rt6_info *ip6_pol_route_lookup(struct net *net,
struct fib6_node *fn;
struct rt6_info *rt;
- if (fl6->flowi6_flags & FLOWI_FLAG_SKIP_NH_OIF)
- flags &= ~RT6_LOOKUP_F_IFACE;
-
rcu_read_lock();
fn = fib6_node_lookup(&table->tb6_root, &fl6->daddr, &fl6->saddr);
restart:
@@ -2182,9 +2179,6 @@ int fib6_table_lookup(struct net *net, struct fib6_table *table, int oif,
fn = fib6_node_lookup(&table->tb6_root, &fl6->daddr, &fl6->saddr);
saved_fn = fn;
- if (fl6->flowi6_flags & FLOWI_FLAG_SKIP_NH_OIF)
- oif = 0;
-
redo_rt6_select:
rt6_select(net, fn, oif, res, strict);
if (res->f6i == net->ipv6.fib6_null_entry) {
@@ -3060,12 +3054,6 @@ INDIRECT_CALLABLE_SCOPE struct rt6_info *__ip6_route_redirect(struct net *net,
struct fib6_info *rt;
struct fib6_node *fn;
- /* l3mdev_update_flow overrides oif if the device is enslaved; in
- * this case we must match on the real ingress device, so reset it
- */
- if (fl6->flowi6_flags & FLOWI_FLAG_SKIP_NH_OIF)
- fl6->flowi6_oif = skb->dev->ifindex;
-
/* Get the "current" route for this destination and
* check if the redirect has come from appropriate router.
*
diff --git a/net/ipv6/xfrm6_policy.c b/net/ipv6/xfrm6_policy.c
index 7c903e0e446cb..492b9692c0dc0 100644
--- a/net/ipv6/xfrm6_policy.c
+++ b/net/ipv6/xfrm6_policy.c
@@ -33,8 +33,7 @@ static struct dst_entry *xfrm6_dst_lookup(struct net *net, int tos, int oif,
int err;
memset(&fl6, 0, sizeof(fl6));
- fl6.flowi6_oif = l3mdev_master_ifindex_by_index(net, oif);
- fl6.flowi6_flags = FLOWI_FLAG_SKIP_NH_OIF;
+ fl6.flowi6_l3mdev = l3mdev_master_ifindex_by_index(net, oif);
fl6.flowi6_mark = mark;
memcpy(&fl6.daddr, daddr, sizeof(fl6.daddr));
if (saddr)
diff --git a/net/l3mdev/l3mdev.c b/net/l3mdev/l3mdev.c
index 8b14a24f10404..ca10916340b09 100644
--- a/net/l3mdev/l3mdev.c
+++ b/net/l3mdev/l3mdev.c
@@ -250,25 +250,19 @@ int l3mdev_fib_rule_match(struct net *net, struct flowi *fl,
struct net_device *dev;
int rc = 0;
- rcu_read_lock();
+ /* update flow ensures flowi_l3mdev is set when relevant */
+ if (!fl->flowi_l3mdev)
+ return 0;
- dev = dev_get_by_index_rcu(net, fl->flowi_oif);
- if (dev && netif_is_l3_master(dev) &&
- dev->l3mdev_ops->l3mdev_fib_table) {
- arg->table = dev->l3mdev_ops->l3mdev_fib_table(dev);
- rc = 1;
- goto out;
- }
+ rcu_read_lock();
- dev = dev_get_by_index_rcu(net, fl->flowi_iif);
+ dev = dev_get_by_index_rcu(net, fl->flowi_l3mdev);
if (dev && netif_is_l3_master(dev) &&
dev->l3mdev_ops->l3mdev_fib_table) {
arg->table = dev->l3mdev_ops->l3mdev_fib_table(dev);
rc = 1;
- goto out;
}
-out:
rcu_read_unlock();
return rc;
@@ -277,31 +271,28 @@ int l3mdev_fib_rule_match(struct net *net, struct flowi *fl,
void l3mdev_update_flow(struct net *net, struct flowi *fl)
{
struct net_device *dev;
- int ifindex;
rcu_read_lock();
if (fl->flowi_oif) {
dev = dev_get_by_index_rcu(net, fl->flowi_oif);
if (dev) {
- ifindex = l3mdev_master_ifindex_rcu(dev);
- if (ifindex) {
- fl->flowi_oif = ifindex;
- fl->flowi_flags |= FLOWI_FLAG_SKIP_NH_OIF;
- goto out;
- }
+ if (!fl->flowi_l3mdev)
+ fl->flowi_l3mdev = l3mdev_master_ifindex_rcu(dev);
+
+ /* oif set to L3mdev directs lookup to its table;
+ * reset to avoid oif match in fib_lookup
+ */
+ if (netif_is_l3_master(dev))
+ fl->flowi_oif = 0;
+ goto out;
}
}
- if (fl->flowi_iif) {
+ if (fl->flowi_iif > LOOPBACK_IFINDEX && !fl->flowi_l3mdev) {
dev = dev_get_by_index_rcu(net, fl->flowi_iif);
- if (dev) {
- ifindex = l3mdev_master_ifindex_rcu(dev);
- if (ifindex) {
- fl->flowi_iif = ifindex;
- fl->flowi_flags |= FLOWI_FLAG_SKIP_NH_OIF;
- }
- }
+ if (dev)
+ fl->flowi_l3mdev = l3mdev_master_ifindex_rcu(dev);
}
out:
diff --git a/tools/testing/selftests/net/fcnal-test.sh b/tools/testing/selftests/net/fcnal-test.sh
index 6ecdbbe1b54fb..bed85001da735 100755
--- a/tools/testing/selftests/net/fcnal-test.sh
+++ b/tools/testing/selftests/net/fcnal-test.sh
@@ -750,7 +750,7 @@ ipv4_ping_vrf()
log_start
show_hint "Fails since address on vrf device is out of device scope"
run_cmd ping -c1 -w1 -I ${NSA_DEV} ${a}
- log_test_addr ${a} $? 1 "ping local, device bind"
+ log_test_addr ${a} $? 2 "ping local, device bind"
done
#
