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9#include <linux/types.h>
10#include <linux/jiffies.h>
11#include <linux/timer.h>
12#include <linux/netfilter.h>
13#include <net/netfilter/nf_conntrack_l4proto.h>
14
15static const unsigned int nf_ct_generic_timeout = 600*HZ;
16
17static bool nf_generic_should_process(u8 proto)
18{
19 switch (proto) {
20#ifdef CONFIG_NF_CT_PROTO_GRE_MODULE
21 case IPPROTO_GRE:
22 return false;
23#endif
24 default:
25 return true;
26 }
27}
28
29static inline struct nf_generic_net *generic_pernet(struct net *net)
30{
31 return &net->ct.nf_ct_proto.generic;
32}
33
34static bool generic_pkt_to_tuple(const struct sk_buff *skb,
35 unsigned int dataoff,
36 struct net *net, struct nf_conntrack_tuple *tuple)
37{
38 tuple->src.u.all = 0;
39 tuple->dst.u.all = 0;
40
41 return true;
42}
43
44static bool generic_invert_tuple(struct nf_conntrack_tuple *tuple,
45 const struct nf_conntrack_tuple *orig)
46{
47 tuple->src.u.all = 0;
48 tuple->dst.u.all = 0;
49
50 return true;
51}
52
53static unsigned int *generic_get_timeouts(struct net *net)
54{
55 return &(generic_pernet(net)->timeout);
56}
57
58
59static int generic_packet(struct nf_conn *ct,
60 const struct sk_buff *skb,
61 unsigned int dataoff,
62 enum ip_conntrack_info ctinfo,
63 unsigned int *timeout)
64{
65 nf_ct_refresh_acct(ct, ctinfo, skb, *timeout);
66 return NF_ACCEPT;
67}
68
69
70static bool generic_new(struct nf_conn *ct, const struct sk_buff *skb,
71 unsigned int dataoff, unsigned int *timeouts)
72{
73 bool ret;
74
75 ret = nf_generic_should_process(nf_ct_protonum(ct));
76 if (!ret)
77 pr_warn_once("conntrack: generic helper won't handle protocol %d. Please consider loading the specific helper module.\n",
78 nf_ct_protonum(ct));
79 return ret;
80}
81
82#if IS_ENABLED(CONFIG_NF_CT_NETLINK_TIMEOUT)
83
84#include <linux/netfilter/nfnetlink.h>
85#include <linux/netfilter/nfnetlink_cttimeout.h>
86
87static int generic_timeout_nlattr_to_obj(struct nlattr *tb[],
88 struct net *net, void *data)
89{
90 unsigned int *timeout = data;
91 struct nf_generic_net *gn = generic_pernet(net);
92
93 if (tb[CTA_TIMEOUT_GENERIC_TIMEOUT])
94 *timeout =
95 ntohl(nla_get_be32(tb[CTA_TIMEOUT_GENERIC_TIMEOUT])) * HZ;
96 else {
97
98 *timeout = gn->timeout;
99 }
100
101 return 0;
102}
103
104static int
105generic_timeout_obj_to_nlattr(struct sk_buff *skb, const void *data)
106{
107 const unsigned int *timeout = data;
108
109 if (nla_put_be32(skb, CTA_TIMEOUT_GENERIC_TIMEOUT, htonl(*timeout / HZ)))
110 goto nla_put_failure;
111
112 return 0;
113
114nla_put_failure:
115 return -ENOSPC;
116}
117
118static const struct nla_policy
119generic_timeout_nla_policy[CTA_TIMEOUT_GENERIC_MAX+1] = {
120 [CTA_TIMEOUT_GENERIC_TIMEOUT] = { .type = NLA_U32 },
121};
122#endif
123
124#ifdef CONFIG_SYSCTL
125static struct ctl_table generic_sysctl_table[] = {
126 {
127 .procname = "nf_conntrack_generic_timeout",
128 .maxlen = sizeof(unsigned int),
129 .mode = 0644,
130 .proc_handler = proc_dointvec_jiffies,
131 },
132 { }
133};
134#endif
135
136static int generic_kmemdup_sysctl_table(struct nf_proto_net *pn,
137 struct nf_generic_net *gn)
138{
139#ifdef CONFIG_SYSCTL
140 pn->ctl_table = kmemdup(generic_sysctl_table,
141 sizeof(generic_sysctl_table),
142 GFP_KERNEL);
143 if (!pn->ctl_table)
144 return -ENOMEM;
145
146 pn->ctl_table[0].data = &gn->timeout;
147#endif
148 return 0;
149}
150
151static int generic_init_net(struct net *net, u_int16_t proto)
152{
153 struct nf_generic_net *gn = generic_pernet(net);
154 struct nf_proto_net *pn = &gn->pn;
155
156 gn->timeout = nf_ct_generic_timeout;
157
158 return generic_kmemdup_sysctl_table(pn, gn);
159}
160
161static struct nf_proto_net *generic_get_net_proto(struct net *net)
162{
163 return &net->ct.nf_ct_proto.generic.pn;
164}
165
166const struct nf_conntrack_l4proto nf_conntrack_l4proto_generic =
167{
168 .l3proto = PF_UNSPEC,
169 .l4proto = 255,
170 .pkt_to_tuple = generic_pkt_to_tuple,
171 .invert_tuple = generic_invert_tuple,
172 .packet = generic_packet,
173 .get_timeouts = generic_get_timeouts,
174 .new = generic_new,
175#if IS_ENABLED(CONFIG_NF_CT_NETLINK_TIMEOUT)
176 .ctnl_timeout = {
177 .nlattr_to_obj = generic_timeout_nlattr_to_obj,
178 .obj_to_nlattr = generic_timeout_obj_to_nlattr,
179 .nlattr_max = CTA_TIMEOUT_GENERIC_MAX,
180 .obj_size = sizeof(unsigned int),
181 .nla_policy = generic_timeout_nla_policy,
182 },
183#endif
184 .init_net = generic_init_net,
185 .get_net_proto = generic_get_net_proto,
186};
187
