1 /* (C) 1999-2001 Paul `Rusty' Russell
2 * (C) 2002-2004 Netfilter Core Team <coreteam@netfilter.org>
3 * (C) 2006-2012 Patrick McHardy <kaber@trash.net>
5 * This program is free software; you can redistribute it and/or modify
6 * it under the terms of the GNU General Public License version 2 as
7 * published by the Free Software Foundation.
10 #include <linux/types.h>
11 #include <linux/timer.h>
12 #include <linux/module.h>
13 #include <linux/udp.h>
14 #include <linux/seq_file.h>
15 #include <linux/skbuff.h>
16 #include <linux/ipv6.h>
17 #include <net/ip6_checksum.h>
18 #include <net/checksum.h>
20 #include <linux/netfilter.h>
21 #include <linux/netfilter_ipv4.h>
22 #include <linux/netfilter_ipv6.h>
23 #include <net/netfilter/nf_conntrack_l4proto.h>
24 #include <net/netfilter/nf_conntrack_ecache.h>
25 #include <net/netfilter/nf_log.h>
26 #include <net/netfilter/ipv4/nf_conntrack_ipv4.h>
27 #include <net/netfilter/ipv6/nf_conntrack_ipv6.h>
29 static unsigned int udp_timeouts[UDP_CT_MAX] = {
30 [UDP_CT_UNREPLIED] = 30*HZ,
31 [UDP_CT_REPLIED] = 180*HZ,
34 static inline struct nf_udp_net *udp_pernet(struct net *net)
36 return &net->ct.nf_ct_proto.udp;
39 static bool udp_pkt_to_tuple(const struct sk_buff *skb,
42 struct nf_conntrack_tuple *tuple)
44 const struct udphdr *hp;
47 /* Actually only need first 4 bytes to get ports. */
48 hp = skb_header_pointer(skb, dataoff, 4, &_hdr);
52 tuple->src.u.udp.port = hp->source;
53 tuple->dst.u.udp.port = hp->dest;
58 static bool udp_invert_tuple(struct nf_conntrack_tuple *tuple,
59 const struct nf_conntrack_tuple *orig)
61 tuple->src.u.udp.port = orig->dst.u.udp.port;
62 tuple->dst.u.udp.port = orig->src.u.udp.port;
66 /* Print out the per-protocol part of the tuple. */
67 static void udp_print_tuple(struct seq_file *s,
68 const struct nf_conntrack_tuple *tuple)
70 seq_printf(s, "sport=%hu dport=%hu ",
71 ntohs(tuple->src.u.udp.port),
72 ntohs(tuple->dst.u.udp.port));
75 static unsigned int *udp_get_timeouts(struct net *net)
77 return udp_pernet(net)->timeouts;
80 /* Returns verdict for packet, and may modify conntracktype */
81 static int udp_packet(struct nf_conn *ct,
82 const struct sk_buff *skb,
84 enum ip_conntrack_info ctinfo,
87 unsigned int *timeouts)
89 /* If we've seen traffic both ways, this is some kind of UDP
90 stream. Extend timeout. */
91 if (test_bit(IPS_SEEN_REPLY_BIT, &ct->status)) {
92 nf_ct_refresh_acct(ct, ctinfo, skb,
93 timeouts[UDP_CT_REPLIED]);
94 /* Also, more likely to be important, and not a probe */
95 if (!test_and_set_bit(IPS_ASSURED_BIT, &ct->status))
96 nf_conntrack_event_cache(IPCT_ASSURED, ct);
98 nf_ct_refresh_acct(ct, ctinfo, skb,
99 timeouts[UDP_CT_UNREPLIED]);
104 /* Called when a new connection for this protocol found. */
105 static bool udp_new(struct nf_conn *ct, const struct sk_buff *skb,
106 unsigned int dataoff, unsigned int *timeouts)
111 static int udp_error(struct net *net, struct nf_conn *tmpl, struct sk_buff *skb,
112 unsigned int dataoff, enum ip_conntrack_info *ctinfo,
114 unsigned int hooknum)
116 unsigned int udplen = skb->len - dataoff;
117 const struct udphdr *hdr;
120 /* Header is too small? */
121 hdr = skb_header_pointer(skb, dataoff, sizeof(_hdr), &_hdr);
123 if (LOG_INVALID(net, IPPROTO_UDP))
124 nf_log_packet(net, pf, 0, skb, NULL, NULL, NULL,
125 "nf_ct_udp: short packet ");
129 /* Truncated/malformed packets */
130 if (ntohs(hdr->len) > udplen || ntohs(hdr->len) < sizeof(*hdr)) {
131 if (LOG_INVALID(net, IPPROTO_UDP))
132 nf_log_packet(net, pf, 0, skb, NULL, NULL, NULL,
133 "nf_ct_udp: truncated/malformed packet ");
137 /* Packet with no checksum */
141 /* Checksum invalid? Ignore.
142 * We skip checking packets on the outgoing path
143 * because the checksum is assumed to be correct.
144 * FIXME: Source route IP option packets --RR */
145 if (net->ct.sysctl_checksum && hooknum == NF_INET_PRE_ROUTING &&
146 nf_checksum(skb, hooknum, dataoff, IPPROTO_UDP, pf)) {
147 if (LOG_INVALID(net, IPPROTO_UDP))
148 nf_log_packet(net, pf, 0, skb, NULL, NULL, NULL,
149 "nf_ct_udp: bad UDP checksum ");
156 #if IS_ENABLED(CONFIG_NF_CT_NETLINK_TIMEOUT)
158 #include <linux/netfilter/nfnetlink.h>
159 #include <linux/netfilter/nfnetlink_cttimeout.h>
161 static int udp_timeout_nlattr_to_obj(struct nlattr *tb[],
162 struct net *net, void *data)
164 unsigned int *timeouts = data;
165 struct nf_udp_net *un = udp_pernet(net);
167 /* set default timeouts for UDP. */
168 timeouts[UDP_CT_UNREPLIED] = un->timeouts[UDP_CT_UNREPLIED];
169 timeouts[UDP_CT_REPLIED] = un->timeouts[UDP_CT_REPLIED];
171 if (tb[CTA_TIMEOUT_UDP_UNREPLIED]) {
172 timeouts[UDP_CT_UNREPLIED] =
173 ntohl(nla_get_be32(tb[CTA_TIMEOUT_UDP_UNREPLIED])) * HZ;
175 if (tb[CTA_TIMEOUT_UDP_REPLIED]) {
176 timeouts[UDP_CT_REPLIED] =
177 ntohl(nla_get_be32(tb[CTA_TIMEOUT_UDP_REPLIED])) * HZ;
183 udp_timeout_obj_to_nlattr(struct sk_buff *skb, const void *data)
185 const unsigned int *timeouts = data;
187 if (nla_put_be32(skb, CTA_TIMEOUT_UDP_UNREPLIED,
188 htonl(timeouts[UDP_CT_UNREPLIED] / HZ)) ||
189 nla_put_be32(skb, CTA_TIMEOUT_UDP_REPLIED,
190 htonl(timeouts[UDP_CT_REPLIED] / HZ)))
191 goto nla_put_failure;
198 static const struct nla_policy
199 udp_timeout_nla_policy[CTA_TIMEOUT_UDP_MAX+1] = {
200 [CTA_TIMEOUT_UDP_UNREPLIED] = { .type = NLA_U32 },
201 [CTA_TIMEOUT_UDP_REPLIED] = { .type = NLA_U32 },
203 #endif /* CONFIG_NF_CT_NETLINK_TIMEOUT */
206 static struct ctl_table udp_sysctl_table[] = {
208 .procname = "nf_conntrack_udp_timeout",
209 .maxlen = sizeof(unsigned int),
211 .proc_handler = proc_dointvec_jiffies,
214 .procname = "nf_conntrack_udp_timeout_stream",
215 .maxlen = sizeof(unsigned int),
217 .proc_handler = proc_dointvec_jiffies,
221 #endif /* CONFIG_SYSCTL */
223 static int udp_kmemdup_sysctl_table(struct nf_proto_net *pn,
224 struct nf_udp_net *un)
229 pn->ctl_table = kmemdup(udp_sysctl_table,
230 sizeof(udp_sysctl_table),
234 pn->ctl_table[0].data = &un->timeouts[UDP_CT_UNREPLIED];
235 pn->ctl_table[1].data = &un->timeouts[UDP_CT_REPLIED];
240 static int udp_init_net(struct net *net, u_int16_t proto)
242 struct nf_udp_net *un = udp_pernet(net);
243 struct nf_proto_net *pn = &un->pn;
248 for (i = 0; i < UDP_CT_MAX; i++)
249 un->timeouts[i] = udp_timeouts[i];
252 return udp_kmemdup_sysctl_table(pn, un);
255 static struct nf_proto_net *udp_get_net_proto(struct net *net)
257 return &net->ct.nf_ct_proto.udp.pn;
260 struct nf_conntrack_l4proto nf_conntrack_l4proto_udp4 __read_mostly =
263 .l4proto = IPPROTO_UDP,
266 .pkt_to_tuple = udp_pkt_to_tuple,
267 .invert_tuple = udp_invert_tuple,
268 .print_tuple = udp_print_tuple,
269 .packet = udp_packet,
270 .get_timeouts = udp_get_timeouts,
273 #if IS_ENABLED(CONFIG_NF_CT_NETLINK)
274 .tuple_to_nlattr = nf_ct_port_tuple_to_nlattr,
275 .nlattr_to_tuple = nf_ct_port_nlattr_to_tuple,
276 .nlattr_tuple_size = nf_ct_port_nlattr_tuple_size,
277 .nla_policy = nf_ct_port_nla_policy,
279 #if IS_ENABLED(CONFIG_NF_CT_NETLINK_TIMEOUT)
281 .nlattr_to_obj = udp_timeout_nlattr_to_obj,
282 .obj_to_nlattr = udp_timeout_obj_to_nlattr,
283 .nlattr_max = CTA_TIMEOUT_UDP_MAX,
284 .obj_size = sizeof(unsigned int) * CTA_TIMEOUT_UDP_MAX,
285 .nla_policy = udp_timeout_nla_policy,
287 #endif /* CONFIG_NF_CT_NETLINK_TIMEOUT */
288 .init_net = udp_init_net,
289 .get_net_proto = udp_get_net_proto,
291 EXPORT_SYMBOL_GPL(nf_conntrack_l4proto_udp4);
293 struct nf_conntrack_l4proto nf_conntrack_l4proto_udp6 __read_mostly =
296 .l4proto = IPPROTO_UDP,
299 .pkt_to_tuple = udp_pkt_to_tuple,
300 .invert_tuple = udp_invert_tuple,
301 .print_tuple = udp_print_tuple,
302 .packet = udp_packet,
303 .get_timeouts = udp_get_timeouts,
306 #if IS_ENABLED(CONFIG_NF_CT_NETLINK)
307 .tuple_to_nlattr = nf_ct_port_tuple_to_nlattr,
308 .nlattr_to_tuple = nf_ct_port_nlattr_to_tuple,
309 .nlattr_tuple_size = nf_ct_port_nlattr_tuple_size,
310 .nla_policy = nf_ct_port_nla_policy,
312 #if IS_ENABLED(CONFIG_NF_CT_NETLINK_TIMEOUT)
314 .nlattr_to_obj = udp_timeout_nlattr_to_obj,
315 .obj_to_nlattr = udp_timeout_obj_to_nlattr,
316 .nlattr_max = CTA_TIMEOUT_UDP_MAX,
317 .obj_size = sizeof(unsigned int) * CTA_TIMEOUT_UDP_MAX,
318 .nla_policy = udp_timeout_nla_policy,
320 #endif /* CONFIG_NF_CT_NETLINK_TIMEOUT */
321 .init_net = udp_init_net,
322 .get_net_proto = udp_get_net_proto,
324 EXPORT_SYMBOL_GPL(nf_conntrack_l4proto_udp6);