[PATCH 6.12 526/567] net: ipv6: ioam6: use consistent dst names

Greg Kroah-Hartman
2026-01-06T17:43:47Z

From: Justin Iurman <justin.iurman@uliege.be>

[ Upstream commit d55acb9732d981c7a8e07dd63089a77d2938e382 ]

Be consistent and use the same terminology as other lwt users: orig_dst
is the dst_entry before the transformation, while dst is either the
dst_entry in the cache or the dst_entry after the transformation

Signed-off-by: Justin Iurman <justin.iurman@uliege.be>
Link: https://patch.msgid.link/20250415112554.23823-2-justin.iurman@uliege.be
Signed-off-by: Paolo Abeni <pabeni@redhat.com>
[Harshit: Backport to 6.12.y]
Stable-dep-of: 99a2ace61b21 ("net: use dst_dev_rcu() in sk_setup_caps()")
Signed-off-by: Harshit Mogalapalli <harshit.m.mogalapalli@oracle.com>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
---
net/ipv6/ioam6_iptunnel.c | 35 ++++++++++++++++++-----------------
1 file changed, 18 insertions(+), 17 deletions(-)

--- a/net/ipv6/ioam6_iptunnel.c
+++ b/net/ipv6/ioam6_iptunnel.c
@@ -338,7 +338,8 @@ static int ioam6_do_encap(struct net *ne

static int ioam6_output(struct net *net, struct sock *sk, struct sk_buff *skb)
{
- struct dst_entry *dst = skb_dst(skb), *cache_dst = NULL;
+ struct dst_entry *orig_dst = skb_dst(skb);
+ struct dst_entry *dst = NULL;
struct ioam6_lwt *ilwt;
int err = -EINVAL;
u32 pkt_cnt;
@@ -346,7 +347,7 @@ static int ioam6_output(struct net *net,
if (skb->protocol != htons(ETH_P_IPV6))
goto drop;

- ilwt = ioam6_lwt_state(dst->lwtstate);
+ ilwt = ioam6_lwt_state(orig_dst->lwtstate);

/* Check for insertion frequency (i.e., "k over n" insertions) */
pkt_cnt = atomic_fetch_inc(&ilwt->pkt_cnt);
@@ -354,7 +355,7 @@ static int ioam6_output(struct net *net,
goto out;

local_bh_disable();
- cache_dst = dst_cache_get(&ilwt->cache);
+ dst = dst_cache_get(&ilwt->cache);
local_bh_enable();

switch (ilwt->mode) {
@@ -364,7 +365,7 @@ do_inline:
if (ipv6_hdr(skb)->nexthdr == NEXTHDR_HOP)
goto out;

- err = ioam6_do_inline(net, skb, &ilwt->tuninfo, cache_dst);
+ err = ioam6_do_inline(net, skb, &ilwt->tuninfo, dst);
if (unlikely(err))
goto drop;

@@ -374,7 +375,7 @@ do_encap:
/* Encapsulation (ip6ip6) */
err = ioam6_do_encap(net, skb, &ilwt->tuninfo,
ilwt->has_tunsrc, &ilwt->tunsrc,
- &ilwt->tundst, cache_dst);
+ &ilwt->tundst, dst);
if (unlikely(err))
goto drop;

@@ -392,7 +393,7 @@ do_encap:
goto drop;
}

- if (unlikely(!cache_dst)) {
+ if (unlikely(!dst)) {
struct ipv6hdr *hdr = ipv6_hdr(skb);
struct flowi6 fl6;

@@ -403,20 +404,20 @@ do_encap:
fl6.flowi6_mark = skb->mark;
fl6.flowi6_proto = hdr->nexthdr;

- cache_dst = ip6_route_output(net, NULL, &fl6);
- if (cache_dst->error) {
- err = cache_dst->error;
+ dst = ip6_route_output(net, NULL, &fl6);
+ if (dst->error) {
+ err = dst->error;
goto drop;
}

/* cache only if we don't create a dst reference loop */
- if (dst->lwtstate != cache_dst->lwtstate) {
+ if (orig_dst->lwtstate != dst->lwtstate) {
local_bh_disable();
- dst_cache_set_ip6(&ilwt->cache, cache_dst, &fl6.saddr);
+ dst_cache_set_ip6(&ilwt->cache, dst, &fl6.saddr);
local_bh_enable();
}

- err = skb_cow_head(skb, LL_RESERVED_SPACE(cache_dst->dev));
+ err = skb_cow_head(skb, LL_RESERVED_SPACE(dst->dev));
if (unlikely(err))
goto drop;
}
@@ -424,16 +425,16 @@ do_encap:
/* avoid lwtunnel_output() reentry loop when destination is the same
* after transformation (e.g., with the inline mode)
*/
- if (dst->lwtstate != cache_dst->lwtstate) {
+ if (orig_dst->lwtstate != dst->lwtstate) {
skb_dst_drop(skb);
- skb_dst_set(skb, cache_dst);
+ skb_dst_set(skb, dst);
return dst_output(net, sk, skb);
}
out:
- dst_release(cache_dst);
- return dst->lwtstate->orig_output(net, sk, skb);
+ dst_release(dst);
+ return orig_dst->lwtstate->orig_output(net, sk, skb);
drop:
- dst_release(cache_dst);
+ dst_release(dst);
kfree_skb(skb);
return err;
}