diff options
| author | Taehee Yoo <ap420073@gmail.com> | 2017-07-19 14:27:33 +0900 |
|---|---|---|
| committer | Pablo Neira Ayuso <pablo@netfilter.org> | 2017-07-24 13:24:46 +0200 |
| commit | 0b35f6031a00329800bacc04085188c300c3a4d8 (patch) | |
| tree | b4e34d6ab10b8b065583f1ce7c75ec05dea5a107 /net/netfilter/xt_TPROXY.c | |
| parent | 9f08ea848117ab521efcfd3e004d8e1a0edc640c (diff) | |
netfilter: Remove duplicated rcu_read_lock.
This patch removes duplicate rcu_read_lock().
1. IPVS part:
According to Julian Anastasov's mention, contexts of ipvs are described
at: http://marc.info/?l=netfilter-devel&m=149562884514072&w=2, in summary:
- packet RX/TX: does not need locks because packets come from hooks.
- sync msg RX: backup server uses RCU locks while registering new
connections.
- ip_vs_ctl.c: configuration get/set, RCU locks needed.
- xt_ipvs.c: It is a netfilter match, running from hook context.
As result, rcu_read_lock and rcu_read_unlock can be removed from:
- ip_vs_core.c: all
- ip_vs_ctl.c:
- only from ip_vs_has_real_service
- ip_vs_ftp.c: all
- ip_vs_proto_sctp.c: all
- ip_vs_proto_tcp.c: all
- ip_vs_proto_udp.c: all
- ip_vs_xmit.c: all (contains only packet processing)
2. Netfilter part:
There are three types of functions that are guaranteed the rcu_read_lock().
First, as result, functions are only called by nf_hook():
- nf_conntrack_broadcast_help(), pptp_expectfn(), set_expected_rtp_rtcp().
- tcpmss_reverse_mtu(), tproxy_laddr4(), tproxy_laddr6().
- match_lookup_rt6(), check_hlist(), hashlimit_mt_common().
- xt_osf_match_packet().
Second, functions that caller already held the rcu_read_lock().
- destroy_conntrack(), ctnetlink_conntrack_event().
- ctnl_timeout_find_get(), nfqnl_nf_hook_drop().
Third, functions that are mixed with type1 and type2.
These functions are called by nf_hook() also these are called by
ordinary functions that already held the rcu_read_lock():
- __ctnetlink_glue_build(), ctnetlink_expect_event().
- ctnetlink_proto_size().
Applied files are below:
- nf_conntrack_broadcast.c, nf_conntrack_core.c, nf_conntrack_netlink.c.
- nf_conntrack_pptp.c, nf_conntrack_sip.c, nfnetlink_cttimeout.c.
- nfnetlink_queue.c, xt_TCPMSS.c, xt_TPROXY.c, xt_addrtype.c.
- xt_connlimit.c, xt_hashlimit.c, xt_osf.c
Detailed calltrace can be found at:
http://marc.info/?l=netfilter-devel&m=149667610710350&w=2
Signed-off-by: Taehee Yoo <ap420073@gmail.com>
Acked-by: Julian Anastasov <ja@ssi.bg>
Signed-off-by: Pablo Neira Ayuso <pablo@netfilter.org>
Diffstat (limited to 'net/netfilter/xt_TPROXY.c')
| -rw-r--r-- | net/netfilter/xt_TPROXY.c | 4 |
1 files changed, 0 insertions, 4 deletions
diff --git a/net/netfilter/xt_TPROXY.c b/net/netfilter/xt_TPROXY.c index d767e35fff6b..2b74f37132fc 100644 --- a/net/netfilter/xt_TPROXY.c +++ b/net/netfilter/xt_TPROXY.c @@ -70,13 +70,11 @@ tproxy_laddr4(struct sk_buff *skb, __be32 user_laddr, __be32 daddr) return user_laddr; laddr = 0; - rcu_read_lock(); indev = __in_dev_get_rcu(skb->dev); for_primary_ifa(indev) { laddr = ifa->ifa_local; break; } endfor_ifa(indev); - rcu_read_unlock(); return laddr ? laddr : daddr; } @@ -391,7 +389,6 @@ tproxy_laddr6(struct sk_buff *skb, const struct in6_addr *user_laddr, return user_laddr; laddr = NULL; - rcu_read_lock(); indev = __in6_dev_get(skb->dev); if (indev) { read_lock_bh(&indev->lock); @@ -404,7 +401,6 @@ tproxy_laddr6(struct sk_buff *skb, const struct in6_addr *user_laddr, } read_unlock_bh(&indev->lock); } - rcu_read_unlock(); return laddr ? laddr : daddr; } |