From: Wei Wang <tracywwnj@gmail.com>
To: David Miller <davem@davemloft.net>, netdev@vger.kernel.org
Cc: Eric Dumazet <edumazet@google.com>,
Martin KaFai Lau <kafai@fb.com>, Wei Wang <weiwan@google.com>
Subject: [PATCH v2 net-next 03/21] net: use loopback dev when generating blackhole route
Date: Sat, 17 Jun 2017 10:42:26 -0700 [thread overview]
Message-ID: <20170617174244.132862-4-tracywwnj@gmail.com> (raw)
In-Reply-To: <20170617174244.132862-1-tracywwnj@gmail.com>
From: Wei Wang <weiwan@google.com>
Existing ipv4/6_blackhole_route() code generates a blackhole route
with dst->dev pointing to the passed in dst->dev.
It is not necessary to hold reference to the passed in dst->dev
because the packets going through this route are dropped anyway.
A loopback interface is good enough so that we don't need to worry about
releasing this dst->dev when this dev is going down.
Signed-off-by: Wei Wang <weiwan@google.com>
Acked-by: Martin KaFai Lau <kafai@fb.com>
---
net/ipv4/route.c | 2 +-
net/ipv6/route.c | 9 +++++----
2 files changed, 6 insertions(+), 5 deletions(-)
diff --git a/net/ipv4/route.c b/net/ipv4/route.c
index 9b38cf18144e..0a843ef2b709 100644
--- a/net/ipv4/route.c
+++ b/net/ipv4/route.c
@@ -2504,7 +2504,7 @@ struct dst_entry *ipv4_blackhole_route(struct net *net, struct dst_entry *dst_or
new->input = dst_discard;
new->output = dst_discard_out;
- new->dev = ort->dst.dev;
+ new->dev = net->loopback_dev;
if (new->dev)
dev_hold(new->dev);
diff --git a/net/ipv6/route.c b/net/ipv6/route.c
index 18fe6e2b88d5..bc1bc91bb969 100644
--- a/net/ipv6/route.c
+++ b/net/ipv6/route.c
@@ -1245,9 +1245,12 @@ EXPORT_SYMBOL_GPL(ip6_route_output_flags);
struct dst_entry *ip6_blackhole_route(struct net *net, struct dst_entry *dst_orig)
{
struct rt6_info *rt, *ort = (struct rt6_info *) dst_orig;
+ struct net_device *loopback_dev = net->loopback_dev;
struct dst_entry *new = NULL;
- rt = dst_alloc(&ip6_dst_blackhole_ops, ort->dst.dev, 1, DST_OBSOLETE_NONE, 0);
+
+ rt = dst_alloc(&ip6_dst_blackhole_ops, loopback_dev, 1,
+ DST_OBSOLETE_NONE, 0);
if (rt) {
rt6_info_init(rt);
@@ -1257,10 +1260,8 @@ struct dst_entry *ip6_blackhole_route(struct net *net, struct dst_entry *dst_ori
new->output = dst_discard_out;
dst_copy_metrics(new, &ort->dst);
- rt->rt6i_idev = ort->rt6i_idev;
- if (rt->rt6i_idev)
- in6_dev_hold(rt->rt6i_idev);
+ rt->rt6i_idev = in6_dev_get(loopback_dev);
rt->rt6i_gateway = ort->rt6i_gateway;
rt->rt6i_flags = ort->rt6i_flags & ~RTF_PCPU;
rt->rt6i_metric = 0;
--
2.13.1.518.g3df882009-goog
next prev parent reply other threads:[~2017-06-17 17:43 UTC|newest]
Thread overview: 23+ messages / expand[flat|nested] mbox.gz Atom feed top
2017-06-17 17:42 [PATCH v2 net-next 00/21] remove dst garbage collector logic Wei Wang
2017-06-17 17:42 ` [PATCH v2 net-next 01/21] ipv6: remove unnecessary dst_hold() in ip6_fragment() Wei Wang
2017-06-17 17:42 ` [PATCH v2 net-next 02/21] udp: call dst_hold_safe() in udp_sk_rx_set_dst() Wei Wang
2017-06-17 17:42 ` Wei Wang [this message]
2017-06-17 17:42 ` [PATCH v2 net-next 04/21] net: introduce DST_NOGC in dst_release() to destroy dst based on refcnt Wei Wang
2017-06-17 17:42 ` [PATCH v2 net-next 05/21] net: introduce a new function dst_dev_put() Wei Wang
2017-06-17 17:42 ` [PATCH v2 net-next 06/21] ipv4: take dst->__refcnt when caching dst in fib Wei Wang
2017-06-17 17:42 ` [PATCH v2 net-next 07/21] ipv4: call dst_dev_put() properly Wei Wang
2017-06-17 17:42 ` [PATCH v2 net-next 08/21] ipv4: call dst_hold_safe() properly Wei Wang
2017-06-17 17:42 ` [PATCH v2 net-next 09/21] ipv4: mark DST_NOGC and remove the operation of dst_free() Wei Wang
2017-06-17 17:42 ` [PATCH v2 net-next 10/21] ipv6: take dst->__refcnt for insertion into fib6 tree Wei Wang
2017-06-17 17:42 ` [PATCH v2 net-next 11/21] ipv6: call dst_dev_put() properly Wei Wang
2017-06-17 17:42 ` [PATCH v2 net-next 12/21] ipv6: call dst_hold_safe() properly Wei Wang
2017-06-17 17:42 ` [PATCH v2 net-next 13/21] ipv6: mark DST_NOGC and remove the operation of dst_free() Wei Wang
2017-06-17 17:42 ` [PATCH v2 net-next 14/21] ipv6: get rid of icmp6 dst garbage collector Wei Wang
2017-06-17 17:42 ` [PATCH v2 net-next 15/21] xfrm: take refcnt of dst when creating struct xfrm_dst bundle Wei Wang
2017-06-17 17:42 ` [PATCH v2 net-next 16/21] decnet: take dst->__refcnt when struct dn_route is created Wei Wang
2017-06-17 17:42 ` [PATCH v2 net-next 17/21] net: remove dst gc related code Wei Wang
2017-06-17 17:42 ` [PATCH v2 net-next 18/21] net: remove DST_NOGC flag Wei Wang
2017-06-17 17:42 ` [PATCH v2 net-next 19/21] net: remove DST_NOCACHE flag Wei Wang
2017-06-17 17:42 ` [PATCH v2 net-next 20/21] net: reorder all the dst flags Wei Wang
2017-06-17 17:42 ` [PATCH v2 net-next 21/21] net: add debug atomic_inc_not_zero() in dst_hold() Wei Wang
2017-06-18 2:55 ` [PATCH v2 net-next 00/21] remove dst garbage collector logic David Miller
Reply instructions:
You may reply publicly to this message via plain-text email
using any one of the following methods:
* Save the following mbox file, import it into your mail client,
and reply-to-all from there: mbox
Avoid top-posting and favor interleaved quoting:
https://en.wikipedia.org/wiki/Posting_style#Interleaved_style
* Reply using the --to, --cc, and --in-reply-to
switches of git-send-email(1):
git send-email \
--in-reply-to=20170617174244.132862-4-tracywwnj@gmail.com \
--to=tracywwnj@gmail.com \
--cc=davem@davemloft.net \
--cc=edumazet@google.com \
--cc=kafai@fb.com \
--cc=netdev@vger.kernel.org \
--cc=weiwan@google.com \
/path/to/YOUR_REPLY
https://kernel.org/pub/software/scm/git/docs/git-send-email.html
* If your mail client supports setting the In-Reply-To header
via mailto: links, try the mailto: link
Be sure your reply has a Subject: header at the top and a blank line
before the message body.
This is a public inbox, see mirroring instructions
for how to clone and mirror all data and code used for this inbox;
as well as URLs for NNTP newsgroup(s).