0b35f6031a
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>
81 lines
2 KiB
C
81 lines
2 KiB
C
/*
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* broadcast connection tracking helper
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*
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* (c) 2005 Patrick McHardy <kaber@trash.net>
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*
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* This program is free software; you can redistribute it and/or
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* modify it under the terms of the GNU General Public License
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* as published by the Free Software Foundation; either version
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* 2 of the License, or (at your option) any later version.
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*/
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#include <linux/module.h>
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#include <linux/ip.h>
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#include <net/route.h>
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#include <linux/inetdevice.h>
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#include <linux/skbuff.h>
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#include <net/netfilter/nf_conntrack.h>
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#include <net/netfilter/nf_conntrack_helper.h>
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#include <net/netfilter/nf_conntrack_expect.h>
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int nf_conntrack_broadcast_help(struct sk_buff *skb,
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unsigned int protoff,
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struct nf_conn *ct,
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enum ip_conntrack_info ctinfo,
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unsigned int timeout)
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{
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struct nf_conntrack_expect *exp;
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struct iphdr *iph = ip_hdr(skb);
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struct rtable *rt = skb_rtable(skb);
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struct in_device *in_dev;
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struct nf_conn_help *help = nfct_help(ct);
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__be32 mask = 0;
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/* we're only interested in locally generated packets */
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if (skb->sk == NULL)
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goto out;
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if (rt == NULL || !(rt->rt_flags & RTCF_BROADCAST))
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goto out;
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if (CTINFO2DIR(ctinfo) != IP_CT_DIR_ORIGINAL)
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goto out;
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in_dev = __in_dev_get_rcu(rt->dst.dev);
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if (in_dev != NULL) {
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for_primary_ifa(in_dev) {
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if (ifa->ifa_broadcast == iph->daddr) {
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mask = ifa->ifa_mask;
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break;
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}
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} endfor_ifa(in_dev);
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}
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if (mask == 0)
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goto out;
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exp = nf_ct_expect_alloc(ct);
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if (exp == NULL)
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goto out;
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exp->tuple = ct->tuplehash[IP_CT_DIR_REPLY].tuple;
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exp->tuple.src.u.udp.port = help->helper->tuple.src.u.udp.port;
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exp->mask.src.u3.ip = mask;
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exp->mask.src.u.udp.port = htons(0xFFFF);
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exp->expectfn = NULL;
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exp->flags = NF_CT_EXPECT_PERMANENT;
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exp->class = NF_CT_EXPECT_CLASS_DEFAULT;
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exp->helper = NULL;
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nf_ct_expect_related(exp);
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nf_ct_expect_put(exp);
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nf_ct_refresh(ct, skb, timeout * HZ);
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out:
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return NF_ACCEPT;
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}
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EXPORT_SYMBOL_GPL(nf_conntrack_broadcast_help);
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MODULE_LICENSE("GPL");
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