![Florian Westphal](/assets/img/avatar_default.png)
This switch (default on) can be used to disable automatic registration of connection tracking functionality in newly created network namespaces. This means that when net namespace goes down (or the tracker protocol module is unloaded) we *might* have to unregister the hooks. We can either add another per-netns variable that tells if the hooks got registered by default, or, alternatively, just call the protocol _put() function and have the callee deal with a possible 'extra' put() operation that doesn't pair with a get() one. This uses the latter approach, i.e. a put() without a get has no effect. Conntrack is still enabled automatically regardless of the new sysctl setting if the new net namespace requires connection tracking, e.g. when NAT rules are created. Signed-off-by: Florian Westphal <fw@strlen.de> Signed-off-by: Pablo Neira Ayuso <pablo@netfilter.org>
109 lines
2.9 KiB
C
109 lines
2.9 KiB
C
/*
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* Copyright (C)2003,2004 USAGI/WIDE Project
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*
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* Header for use in defining a given L3 protocol for connection tracking.
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*
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* Author:
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* Yasuyuki Kozakai @USAGI <yasuyuki.kozakai@toshiba.co.jp>
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*
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* Derived from include/netfilter_ipv4/ip_conntrack_protocol.h
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*/
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#ifndef _NF_CONNTRACK_L3PROTO_H
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#define _NF_CONNTRACK_L3PROTO_H
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#include <linux/netlink.h>
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#include <net/netlink.h>
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#include <linux/seq_file.h>
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#include <net/netfilter/nf_conntrack.h>
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struct nf_conntrack_l3proto {
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/* L3 Protocol Family number. ex) PF_INET */
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u_int16_t l3proto;
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/* Protocol name */
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const char *name;
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/*
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* Try to fill in the third arg: nhoff is offset of l3 proto
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* hdr. Return true if possible.
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*/
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bool (*pkt_to_tuple)(const struct sk_buff *skb, unsigned int nhoff,
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struct nf_conntrack_tuple *tuple);
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/*
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* Invert the per-proto part of the tuple: ie. turn xmit into reply.
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* Some packets can't be inverted: return 0 in that case.
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*/
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bool (*invert_tuple)(struct nf_conntrack_tuple *inverse,
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const struct nf_conntrack_tuple *orig);
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/* Print out the per-protocol part of the tuple. */
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void (*print_tuple)(struct seq_file *s,
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const struct nf_conntrack_tuple *);
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/*
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* Called before tracking.
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* *dataoff: offset of protocol header (TCP, UDP,...) in skb
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* *protonum: protocol number
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*/
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int (*get_l4proto)(const struct sk_buff *skb, unsigned int nhoff,
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unsigned int *dataoff, u_int8_t *protonum);
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int (*tuple_to_nlattr)(struct sk_buff *skb,
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const struct nf_conntrack_tuple *t);
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/* Called when netns wants to use connection tracking */
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int (*net_ns_get)(struct net *);
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void (*net_ns_put)(struct net *);
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/*
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* Calculate size of tuple nlattr
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*/
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int (*nlattr_tuple_size)(void);
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int (*nlattr_to_tuple)(struct nlattr *tb[],
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struct nf_conntrack_tuple *t);
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const struct nla_policy *nla_policy;
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size_t nla_size;
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/* Module (if any) which this is connected to. */
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struct module *me;
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};
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extern struct nf_conntrack_l3proto __rcu *nf_ct_l3protos[AF_MAX];
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#ifdef CONFIG_SYSCTL
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/* Protocol pernet registration. */
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int nf_ct_l3proto_pernet_register(struct net *net,
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struct nf_conntrack_l3proto *proto);
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#else
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static inline int nf_ct_l3proto_pernet_register(struct net *n,
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struct nf_conntrack_l3proto *p)
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{
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return 0;
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}
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#endif
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void nf_ct_l3proto_pernet_unregister(struct net *net,
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struct nf_conntrack_l3proto *proto);
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/* Protocol global registration. */
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int nf_ct_l3proto_register(struct nf_conntrack_l3proto *proto);
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void nf_ct_l3proto_unregister(struct nf_conntrack_l3proto *proto);
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struct nf_conntrack_l3proto *nf_ct_l3proto_find_get(u_int16_t l3proto);
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/* Existing built-in protocols */
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extern struct nf_conntrack_l3proto nf_conntrack_l3proto_generic;
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static inline struct nf_conntrack_l3proto *
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__nf_ct_l3proto_find(u_int16_t l3proto)
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{
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if (unlikely(l3proto >= AF_MAX))
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return &nf_conntrack_l3proto_generic;
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return rcu_dereference(nf_ct_l3protos[l3proto]);
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}
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#endif /*_NF_CONNTRACK_L3PROTO_H*/
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