1 /* (C) 1999-2001 Paul `Rusty' Russell
2 * (C) 2002-2004 Netfilter Core Team <coreteam@netfilter.org>
3 *
4 * This program is free software; you can redistribute it and/or modify
5 * it under the terms of the GNU General Public License version 2 as
6 * published by the Free Software Foundation.
7 */
8
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
15 static unsigned int nf_ct_generic_timeout __read_mostly = 600*HZ;
16
nf_generic_should_process(u8 proto)17 static bool nf_generic_should_process(u8 proto)
18 {
19 switch (proto) {
20 #ifdef CONFIG_NF_CT_PROTO_SCTP_MODULE
21 case IPPROTO_SCTP:
22 return false;
23 #endif
24 #ifdef CONFIG_NF_CT_PROTO_DCCP_MODULE
25 case IPPROTO_DCCP:
26 return false;
27 #endif
28 #ifdef CONFIG_NF_CT_PROTO_GRE_MODULE
29 case IPPROTO_GRE:
30 return false;
31 #endif
32 #ifdef CONFIG_NF_CT_PROTO_UDPLITE_MODULE
33 case IPPROTO_UDPLITE:
34 return false;
35 #endif
36 default:
37 return true;
38 }
39 }
40
generic_pernet(struct net * net)41 static inline struct nf_generic_net *generic_pernet(struct net *net)
42 {
43 return &net->ct.nf_ct_proto.generic;
44 }
45
generic_pkt_to_tuple(const struct sk_buff * skb,unsigned int dataoff,struct net * net,struct nf_conntrack_tuple * tuple)46 static bool generic_pkt_to_tuple(const struct sk_buff *skb,
47 unsigned int dataoff,
48 struct net *net, struct nf_conntrack_tuple *tuple)
49 {
50 tuple->src.u.all = 0;
51 tuple->dst.u.all = 0;
52
53 return true;
54 }
55
generic_invert_tuple(struct nf_conntrack_tuple * tuple,const struct nf_conntrack_tuple * orig)56 static bool generic_invert_tuple(struct nf_conntrack_tuple *tuple,
57 const struct nf_conntrack_tuple *orig)
58 {
59 tuple->src.u.all = 0;
60 tuple->dst.u.all = 0;
61
62 return true;
63 }
64
65 /* Print out the per-protocol part of the tuple. */
generic_print_tuple(struct seq_file * s,const struct nf_conntrack_tuple * tuple)66 static void generic_print_tuple(struct seq_file *s,
67 const struct nf_conntrack_tuple *tuple)
68 {
69 }
70
generic_get_timeouts(struct net * net)71 static unsigned int *generic_get_timeouts(struct net *net)
72 {
73 return &(generic_pernet(net)->timeout);
74 }
75
76 /* Returns verdict for packet, or -1 for invalid. */
generic_packet(struct nf_conn * ct,const struct sk_buff * skb,unsigned int dataoff,enum ip_conntrack_info ctinfo,u_int8_t pf,unsigned int hooknum,unsigned int * timeout)77 static int generic_packet(struct nf_conn *ct,
78 const struct sk_buff *skb,
79 unsigned int dataoff,
80 enum ip_conntrack_info ctinfo,
81 u_int8_t pf,
82 unsigned int hooknum,
83 unsigned int *timeout)
84 {
85 nf_ct_refresh_acct(ct, ctinfo, skb, *timeout);
86 return NF_ACCEPT;
87 }
88
89 /* Called when a new connection for this protocol found. */
generic_new(struct nf_conn * ct,const struct sk_buff * skb,unsigned int dataoff,unsigned int * timeouts)90 static bool generic_new(struct nf_conn *ct, const struct sk_buff *skb,
91 unsigned int dataoff, unsigned int *timeouts)
92 {
93 bool ret;
94
95 ret = nf_generic_should_process(nf_ct_protonum(ct));
96 if (!ret)
97 pr_warn_once("conntrack: generic helper won't handle protocol %d. Please consider loading the specific helper module.\n",
98 nf_ct_protonum(ct));
99 return ret;
100 }
101
102 #if IS_ENABLED(CONFIG_NF_CT_NETLINK_TIMEOUT)
103
104 #include <linux/netfilter/nfnetlink.h>
105 #include <linux/netfilter/nfnetlink_cttimeout.h>
106
generic_timeout_nlattr_to_obj(struct nlattr * tb[],struct net * net,void * data)107 static int generic_timeout_nlattr_to_obj(struct nlattr *tb[],
108 struct net *net, void *data)
109 {
110 unsigned int *timeout = data;
111 struct nf_generic_net *gn = generic_pernet(net);
112
113 if (tb[CTA_TIMEOUT_GENERIC_TIMEOUT])
114 *timeout =
115 ntohl(nla_get_be32(tb[CTA_TIMEOUT_GENERIC_TIMEOUT])) * HZ;
116 else {
117 /* Set default generic timeout. */
118 *timeout = gn->timeout;
119 }
120
121 return 0;
122 }
123
124 static int
generic_timeout_obj_to_nlattr(struct sk_buff * skb,const void * data)125 generic_timeout_obj_to_nlattr(struct sk_buff *skb, const void *data)
126 {
127 const unsigned int *timeout = data;
128
129 if (nla_put_be32(skb, CTA_TIMEOUT_GENERIC_TIMEOUT, htonl(*timeout / HZ)))
130 goto nla_put_failure;
131
132 return 0;
133
134 nla_put_failure:
135 return -ENOSPC;
136 }
137
138 static const struct nla_policy
139 generic_timeout_nla_policy[CTA_TIMEOUT_GENERIC_MAX+1] = {
140 [CTA_TIMEOUT_GENERIC_TIMEOUT] = { .type = NLA_U32 },
141 };
142 #endif /* CONFIG_NF_CT_NETLINK_TIMEOUT */
143
144 #ifdef CONFIG_SYSCTL
145 static struct ctl_table generic_sysctl_table[] = {
146 {
147 .procname = "nf_conntrack_generic_timeout",
148 .maxlen = sizeof(unsigned int),
149 .mode = 0644,
150 .proc_handler = proc_dointvec_jiffies,
151 },
152 { }
153 };
154 #endif /* CONFIG_SYSCTL */
155
generic_kmemdup_sysctl_table(struct nf_proto_net * pn,struct nf_generic_net * gn)156 static int generic_kmemdup_sysctl_table(struct nf_proto_net *pn,
157 struct nf_generic_net *gn)
158 {
159 #ifdef CONFIG_SYSCTL
160 pn->ctl_table = kmemdup(generic_sysctl_table,
161 sizeof(generic_sysctl_table),
162 GFP_KERNEL);
163 if (!pn->ctl_table)
164 return -ENOMEM;
165
166 pn->ctl_table[0].data = &gn->timeout;
167 #endif
168 return 0;
169 }
170
generic_init_net(struct net * net,u_int16_t proto)171 static int generic_init_net(struct net *net, u_int16_t proto)
172 {
173 struct nf_generic_net *gn = generic_pernet(net);
174 struct nf_proto_net *pn = &gn->pn;
175
176 gn->timeout = nf_ct_generic_timeout;
177
178 return generic_kmemdup_sysctl_table(pn, gn);
179 }
180
generic_get_net_proto(struct net * net)181 static struct nf_proto_net *generic_get_net_proto(struct net *net)
182 {
183 return &net->ct.nf_ct_proto.generic.pn;
184 }
185
186 struct nf_conntrack_l4proto nf_conntrack_l4proto_generic __read_mostly =
187 {
188 .l3proto = PF_UNSPEC,
189 .l4proto = 255,
190 .name = "unknown",
191 .pkt_to_tuple = generic_pkt_to_tuple,
192 .invert_tuple = generic_invert_tuple,
193 .print_tuple = generic_print_tuple,
194 .packet = generic_packet,
195 .get_timeouts = generic_get_timeouts,
196 .new = generic_new,
197 #if IS_ENABLED(CONFIG_NF_CT_NETLINK_TIMEOUT)
198 .ctnl_timeout = {
199 .nlattr_to_obj = generic_timeout_nlattr_to_obj,
200 .obj_to_nlattr = generic_timeout_obj_to_nlattr,
201 .nlattr_max = CTA_TIMEOUT_GENERIC_MAX,
202 .obj_size = sizeof(unsigned int),
203 .nla_policy = generic_timeout_nla_policy,
204 },
205 #endif /* CONFIG_NF_CT_NETLINK_TIMEOUT */
206 .init_net = generic_init_net,
207 .get_net_proto = generic_get_net_proto,
208 };
209