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802a7dc5cf
(struct nf_conn)->timeout can be read/written locklessly,
add READ_ONCE()/WRITE_ONCE() to prevent load/store tearing.
BUG: KCSAN: data-race in __nf_conntrack_alloc / __nf_conntrack_find_get
write to 0xffff888132e78c08 of 4 bytes by task 6029 on cpu 0:
__nf_conntrack_alloc+0x158/0x280 net/netfilter/nf_conntrack_core.c:1563
init_conntrack+0x1da/0xb30 net/netfilter/nf_conntrack_core.c:1635
resolve_normal_ct+0x502/0x610 net/netfilter/nf_conntrack_core.c:1746
nf_conntrack_in+0x1c5/0x88f net/netfilter/nf_conntrack_core.c:1901
ipv6_conntrack_local+0x19/0x20 net/netfilter/nf_conntrack_proto.c:414
nf_hook_entry_hookfn include/linux/netfilter.h:142 [inline]
nf_hook_slow+0x72/0x170 net/netfilter/core.c:619
nf_hook include/linux/netfilter.h:262 [inline]
NF_HOOK include/linux/netfilter.h:305 [inline]
ip6_xmit+0xa3a/0xa60 net/ipv6/ip6_output.c:324
inet6_csk_xmit+0x1a2/0x1e0 net/ipv6/inet6_connection_sock.c:135
__tcp_transmit_skb+0x132a/0x1840 net/ipv4/tcp_output.c:1402
tcp_transmit_skb net/ipv4/tcp_output.c:1420 [inline]
tcp_write_xmit+0x1450/0x4460 net/ipv4/tcp_output.c:2680
__tcp_push_pending_frames+0x68/0x1c0 net/ipv4/tcp_output.c:2864
tcp_push_pending_frames include/net/tcp.h:1897 [inline]
tcp_data_snd_check+0x62/0x2e0 net/ipv4/tcp_input.c:5452
tcp_rcv_established+0x880/0x10e0 net/ipv4/tcp_input.c:5947
tcp_v6_do_rcv+0x36e/0xa50 net/ipv6/tcp_ipv6.c:1521
sk_backlog_rcv include/net/sock.h:1030 [inline]
__release_sock+0xf2/0x270 net/core/sock.c:2768
release_sock+0x40/0x110 net/core/sock.c:3300
sk_stream_wait_memory+0x435/0x700 net/core/stream.c:145
tcp_sendmsg_locked+0xb85/0x25a0 net/ipv4/tcp.c:1402
tcp_sendmsg+0x2c/0x40 net/ipv4/tcp.c:1440
inet6_sendmsg+0x5f/0x80 net/ipv6/af_inet6.c:644
sock_sendmsg_nosec net/socket.c:704 [inline]
sock_sendmsg net/socket.c:724 [inline]
__sys_sendto+0x21e/0x2c0 net/socket.c:2036
__do_sys_sendto net/socket.c:2048 [inline]
__se_sys_sendto net/socket.c:2044 [inline]
__x64_sys_sendto+0x74/0x90 net/socket.c:2044
do_syscall_x64 arch/x86/entry/common.c:50 [inline]
do_syscall_64+0x44/0xd0 arch/x86/entry/common.c:80
entry_SYSCALL_64_after_hwframe+0x44/0xae
read to 0xffff888132e78c08 of 4 bytes by task 17446 on cpu 1:
nf_ct_is_expired include/net/netfilter/nf_conntrack.h:286 [inline]
____nf_conntrack_find net/netfilter/nf_conntrack_core.c:776 [inline]
__nf_conntrack_find_get+0x1c7/0xac0 net/netfilter/nf_conntrack_core.c:807
resolve_normal_ct+0x273/0x610 net/netfilter/nf_conntrack_core.c:1734
nf_conntrack_in+0x1c5/0x88f net/netfilter/nf_conntrack_core.c:1901
ipv6_conntrack_local+0x19/0x20 net/netfilter/nf_conntrack_proto.c:414
nf_hook_entry_hookfn include/linux/netfilter.h:142 [inline]
nf_hook_slow+0x72/0x170 net/netfilter/core.c:619
nf_hook include/linux/netfilter.h:262 [inline]
NF_HOOK include/linux/netfilter.h:305 [inline]
ip6_xmit+0xa3a/0xa60 net/ipv6/ip6_output.c:324
inet6_csk_xmit+0x1a2/0x1e0 net/ipv6/inet6_connection_sock.c:135
__tcp_transmit_skb+0x132a/0x1840 net/ipv4/tcp_output.c:1402
__tcp_send_ack+0x1fd/0x300 net/ipv4/tcp_output.c:3956
tcp_send_ack+0x23/0x30 net/ipv4/tcp_output.c:3962
__tcp_ack_snd_check+0x2d8/0x510 net/ipv4/tcp_input.c:5478
tcp_ack_snd_check net/ipv4/tcp_input.c:5523 [inline]
tcp_rcv_established+0x8c2/0x10e0 net/ipv4/tcp_input.c:5948
tcp_v6_do_rcv+0x36e/0xa50 net/ipv6/tcp_ipv6.c:1521
sk_backlog_rcv include/net/sock.h:1030 [inline]
__release_sock+0xf2/0x270 net/core/sock.c:2768
release_sock+0x40/0x110 net/core/sock.c:3300
tcp_sendpage+0x94/0xb0 net/ipv4/tcp.c:1114
inet_sendpage+0x7f/0xc0 net/ipv4/af_inet.c:833
rds_tcp_xmit+0x376/0x5f0 net/rds/tcp_send.c:118
rds_send_xmit+0xbed/0x1500 net/rds/send.c:367
rds_send_worker+0x43/0x200 net/rds/threads.c:200
process_one_work+0x3fc/0x980 kernel/workqueue.c:2298
worker_thread+0x616/0xa70 kernel/workqueue.c:2445
kthread+0x2c7/0x2e0 kernel/kthread.c:327
ret_from_fork+0x1f/0x30
value changed: 0x00027cc2 -> 0x00000000
Reported by Kernel Concurrency Sanitizer on:
CPU: 1 PID: 17446 Comm: kworker/u4:5 Tainted: G W 5.16.0-rc4-syzkaller #0
Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 01/01/2011
Workqueue: krdsd rds_send_worker
Note: I chose an arbitrary commit for the Fixes: tag,
because I do not think we need to backport this fix to very old kernels.
Fixes: e37542ba11
("netfilter: conntrack: avoid possible false sharing")
Signed-off-by: Eric Dumazet <edumazet@google.com>
Reported-by: syzbot <syzkaller@googlegroups.com>
Signed-off-by: Pablo Neira Ayuso <pablo@netfilter.org>
363 lines
10 KiB
C
363 lines
10 KiB
C
/* SPDX-License-Identifier: GPL-2.0 */
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/*
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* Connection state tracking for netfilter. This is separated from,
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* but required by, the (future) NAT layer; it can also be used by an iptables
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* extension.
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*
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* 16 Dec 2003: Yasuyuki Kozakai @USAGI <yasuyuki.kozakai@toshiba.co.jp>
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* - generalize L3 protocol dependent part.
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*
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* Derived from include/linux/netfiter_ipv4/ip_conntrack.h
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*/
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#ifndef _NF_CONNTRACK_H
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#define _NF_CONNTRACK_H
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#include <linux/bitops.h>
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#include <linux/compiler.h>
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#include <linux/netfilter/nf_conntrack_common.h>
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#include <linux/netfilter/nf_conntrack_tcp.h>
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#include <linux/netfilter/nf_conntrack_dccp.h>
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#include <linux/netfilter/nf_conntrack_sctp.h>
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#include <linux/netfilter/nf_conntrack_proto_gre.h>
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#include <net/netfilter/nf_conntrack_tuple.h>
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struct nf_ct_udp {
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unsigned long stream_ts;
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};
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/* per conntrack: protocol private data */
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union nf_conntrack_proto {
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/* insert conntrack proto private data here */
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struct nf_ct_dccp dccp;
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struct ip_ct_sctp sctp;
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struct ip_ct_tcp tcp;
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struct nf_ct_udp udp;
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struct nf_ct_gre gre;
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unsigned int tmpl_padto;
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};
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union nf_conntrack_expect_proto {
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/* insert expect proto private data here */
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};
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struct nf_conntrack_net {
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/* only used when new connection is allocated: */
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atomic_t count;
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unsigned int expect_count;
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u8 sysctl_auto_assign_helper;
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bool auto_assign_helper_warned;
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/* only used from work queues, configuration plane, and so on: */
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unsigned int users4;
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unsigned int users6;
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unsigned int users_bridge;
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#ifdef CONFIG_SYSCTL
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struct ctl_table_header *sysctl_header;
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#endif
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#ifdef CONFIG_NF_CONNTRACK_EVENTS
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struct delayed_work ecache_dwork;
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struct netns_ct *ct_net;
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#endif
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};
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#include <linux/types.h>
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#include <linux/skbuff.h>
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#include <net/netfilter/ipv4/nf_conntrack_ipv4.h>
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#include <net/netfilter/ipv6/nf_conntrack_ipv6.h>
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struct nf_conn {
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/* Usage count in here is 1 for hash table, 1 per skb,
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* plus 1 for any connection(s) we are `master' for
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*
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* Hint, SKB address this struct and refcnt via skb->_nfct and
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* helpers nf_conntrack_get() and nf_conntrack_put().
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* Helper nf_ct_put() equals nf_conntrack_put() by dec refcnt,
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* beware nf_ct_get() is different and don't inc refcnt.
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*/
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struct nf_conntrack ct_general;
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spinlock_t lock;
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/* jiffies32 when this ct is considered dead */
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u32 timeout;
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#ifdef CONFIG_NF_CONNTRACK_ZONES
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struct nf_conntrack_zone zone;
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#endif
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/* XXX should I move this to the tail ? - Y.K */
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/* These are my tuples; original and reply */
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struct nf_conntrack_tuple_hash tuplehash[IP_CT_DIR_MAX];
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/* Have we seen traffic both ways yet? (bitset) */
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unsigned long status;
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u16 cpu;
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possible_net_t ct_net;
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#if IS_ENABLED(CONFIG_NF_NAT)
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struct hlist_node nat_bysource;
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#endif
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/* all members below initialized via memset */
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struct { } __nfct_init_offset;
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/* If we were expected by an expectation, this will be it */
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struct nf_conn *master;
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#if defined(CONFIG_NF_CONNTRACK_MARK)
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u_int32_t mark;
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#endif
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#ifdef CONFIG_NF_CONNTRACK_SECMARK
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u_int32_t secmark;
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#endif
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/* Extensions */
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struct nf_ct_ext *ext;
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/* Storage reserved for other modules, must be the last member */
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union nf_conntrack_proto proto;
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};
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static inline struct nf_conn *
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nf_ct_tuplehash_to_ctrack(const struct nf_conntrack_tuple_hash *hash)
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{
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return container_of(hash, struct nf_conn,
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tuplehash[hash->tuple.dst.dir]);
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}
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static inline u_int16_t nf_ct_l3num(const struct nf_conn *ct)
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{
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return ct->tuplehash[IP_CT_DIR_ORIGINAL].tuple.src.l3num;
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}
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static inline u_int8_t nf_ct_protonum(const struct nf_conn *ct)
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{
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return ct->tuplehash[IP_CT_DIR_ORIGINAL].tuple.dst.protonum;
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}
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#define nf_ct_tuple(ct, dir) (&(ct)->tuplehash[dir].tuple)
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/* get master conntrack via master expectation */
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#define master_ct(conntr) (conntr->master)
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extern struct net init_net;
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static inline struct net *nf_ct_net(const struct nf_conn *ct)
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{
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return read_pnet(&ct->ct_net);
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}
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/* Alter reply tuple (maybe alter helper). */
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void nf_conntrack_alter_reply(struct nf_conn *ct,
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const struct nf_conntrack_tuple *newreply);
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/* Is this tuple taken? (ignoring any belonging to the given
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conntrack). */
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int nf_conntrack_tuple_taken(const struct nf_conntrack_tuple *tuple,
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const struct nf_conn *ignored_conntrack);
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/* Return conntrack_info and tuple hash for given skb. */
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static inline struct nf_conn *
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nf_ct_get(const struct sk_buff *skb, enum ip_conntrack_info *ctinfo)
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{
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unsigned long nfct = skb_get_nfct(skb);
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*ctinfo = nfct & NFCT_INFOMASK;
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return (struct nf_conn *)(nfct & NFCT_PTRMASK);
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}
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/* decrement reference count on a conntrack */
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static inline void nf_ct_put(struct nf_conn *ct)
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{
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WARN_ON(!ct);
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nf_conntrack_put(&ct->ct_general);
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}
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/* Protocol module loading */
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int nf_ct_l3proto_try_module_get(unsigned short l3proto);
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void nf_ct_l3proto_module_put(unsigned short l3proto);
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/* load module; enable/disable conntrack in this namespace */
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int nf_ct_netns_get(struct net *net, u8 nfproto);
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void nf_ct_netns_put(struct net *net, u8 nfproto);
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/*
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* Allocate a hashtable of hlist_head (if nulls == 0),
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* or hlist_nulls_head (if nulls == 1)
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*/
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void *nf_ct_alloc_hashtable(unsigned int *sizep, int nulls);
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int nf_conntrack_hash_check_insert(struct nf_conn *ct);
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bool nf_ct_delete(struct nf_conn *ct, u32 pid, int report);
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bool nf_ct_get_tuplepr(const struct sk_buff *skb, unsigned int nhoff,
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u_int16_t l3num, struct net *net,
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struct nf_conntrack_tuple *tuple);
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void __nf_ct_refresh_acct(struct nf_conn *ct, enum ip_conntrack_info ctinfo,
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const struct sk_buff *skb,
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u32 extra_jiffies, bool do_acct);
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/* Refresh conntrack for this many jiffies and do accounting */
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static inline void nf_ct_refresh_acct(struct nf_conn *ct,
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enum ip_conntrack_info ctinfo,
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const struct sk_buff *skb,
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u32 extra_jiffies)
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{
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__nf_ct_refresh_acct(ct, ctinfo, skb, extra_jiffies, true);
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}
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/* Refresh conntrack for this many jiffies */
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static inline void nf_ct_refresh(struct nf_conn *ct,
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const struct sk_buff *skb,
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u32 extra_jiffies)
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{
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__nf_ct_refresh_acct(ct, 0, skb, extra_jiffies, false);
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}
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/* kill conntrack and do accounting */
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bool nf_ct_kill_acct(struct nf_conn *ct, enum ip_conntrack_info ctinfo,
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const struct sk_buff *skb);
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/* kill conntrack without accounting */
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static inline bool nf_ct_kill(struct nf_conn *ct)
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{
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return nf_ct_delete(ct, 0, 0);
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}
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/* Set all unconfirmed conntrack as dying */
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void nf_ct_unconfirmed_destroy(struct net *);
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/* Iterate over all conntracks: if iter returns true, it's deleted. */
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void nf_ct_iterate_cleanup_net(struct net *net,
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int (*iter)(struct nf_conn *i, void *data),
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void *data, u32 portid, int report);
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/* also set unconfirmed conntracks as dying. Only use in module exit path. */
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void nf_ct_iterate_destroy(int (*iter)(struct nf_conn *i, void *data),
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void *data);
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struct nf_conntrack_zone;
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void nf_conntrack_free(struct nf_conn *ct);
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struct nf_conn *nf_conntrack_alloc(struct net *net,
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const struct nf_conntrack_zone *zone,
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const struct nf_conntrack_tuple *orig,
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const struct nf_conntrack_tuple *repl,
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gfp_t gfp);
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static inline int nf_ct_is_template(const struct nf_conn *ct)
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{
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return test_bit(IPS_TEMPLATE_BIT, &ct->status);
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}
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/* It's confirmed if it is, or has been in the hash table. */
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static inline int nf_ct_is_confirmed(const struct nf_conn *ct)
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{
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return test_bit(IPS_CONFIRMED_BIT, &ct->status);
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}
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static inline int nf_ct_is_dying(const struct nf_conn *ct)
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{
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return test_bit(IPS_DYING_BIT, &ct->status);
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}
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/* Packet is received from loopback */
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static inline bool nf_is_loopback_packet(const struct sk_buff *skb)
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{
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return skb->dev && skb->skb_iif && skb->dev->flags & IFF_LOOPBACK;
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}
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#define nfct_time_stamp ((u32)(jiffies))
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/* jiffies until ct expires, 0 if already expired */
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static inline unsigned long nf_ct_expires(const struct nf_conn *ct)
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{
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s32 timeout = READ_ONCE(ct->timeout) - nfct_time_stamp;
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return timeout > 0 ? timeout : 0;
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}
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static inline bool nf_ct_is_expired(const struct nf_conn *ct)
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{
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return (__s32)(READ_ONCE(ct->timeout) - nfct_time_stamp) <= 0;
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}
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/* use after obtaining a reference count */
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static inline bool nf_ct_should_gc(const struct nf_conn *ct)
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{
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return nf_ct_is_expired(ct) && nf_ct_is_confirmed(ct) &&
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!nf_ct_is_dying(ct);
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}
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#define NF_CT_DAY (86400 * HZ)
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/* Set an arbitrary timeout large enough not to ever expire, this save
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* us a check for the IPS_OFFLOAD_BIT from the packet path via
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* nf_ct_is_expired().
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*/
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static inline void nf_ct_offload_timeout(struct nf_conn *ct)
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{
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if (nf_ct_expires(ct) < NF_CT_DAY / 2)
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WRITE_ONCE(ct->timeout, nfct_time_stamp + NF_CT_DAY);
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}
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struct kernel_param;
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int nf_conntrack_set_hashsize(const char *val, const struct kernel_param *kp);
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int nf_conntrack_hash_resize(unsigned int hashsize);
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extern struct hlist_nulls_head *nf_conntrack_hash;
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extern unsigned int nf_conntrack_htable_size;
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extern seqcount_spinlock_t nf_conntrack_generation;
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extern unsigned int nf_conntrack_max;
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/* must be called with rcu read lock held */
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static inline void
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nf_conntrack_get_ht(struct hlist_nulls_head **hash, unsigned int *hsize)
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{
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struct hlist_nulls_head *hptr;
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unsigned int sequence, hsz;
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do {
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sequence = read_seqcount_begin(&nf_conntrack_generation);
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hsz = nf_conntrack_htable_size;
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hptr = nf_conntrack_hash;
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} while (read_seqcount_retry(&nf_conntrack_generation, sequence));
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*hash = hptr;
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*hsize = hsz;
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}
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struct nf_conn *nf_ct_tmpl_alloc(struct net *net,
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const struct nf_conntrack_zone *zone,
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gfp_t flags);
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void nf_ct_tmpl_free(struct nf_conn *tmpl);
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u32 nf_ct_get_id(const struct nf_conn *ct);
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u32 nf_conntrack_count(const struct net *net);
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static inline void
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nf_ct_set(struct sk_buff *skb, struct nf_conn *ct, enum ip_conntrack_info info)
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{
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skb_set_nfct(skb, (unsigned long)ct | info);
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}
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extern unsigned int nf_conntrack_net_id;
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static inline struct nf_conntrack_net *nf_ct_pernet(const struct net *net)
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{
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return net_generic(net, nf_conntrack_net_id);
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}
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#define NF_CT_STAT_INC(net, count) __this_cpu_inc((net)->ct.stat->count)
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#define NF_CT_STAT_INC_ATOMIC(net, count) this_cpu_inc((net)->ct.stat->count)
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#define NF_CT_STAT_ADD_ATOMIC(net, count, v) this_cpu_add((net)->ct.stat->count, (v))
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#define MODULE_ALIAS_NFCT_HELPER(helper) \
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MODULE_ALIAS("nfct-helper-" helper)
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#endif /* _NF_CONNTRACK_H */
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