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,
41 struct nf_conntrack_tuple *tuple)
43 const struct udphdr *hp;
46 /* Actually only need first 8 bytes. */
47 hp = skb_header_pointer(skb, dataoff, sizeof(_hdr), &_hdr);
51 tuple->src.u.udp.port = hp->source;
52 tuple->dst.u.udp.port = hp->dest;
57 static bool udp_invert_tuple(struct nf_conntrack_tuple *tuple,
58 const struct nf_conntrack_tuple *orig)
60 tuple->src.u.udp.port = orig->dst.u.udp.port;
61 tuple->dst.u.udp.port = orig->src.u.udp.port;
65 /* Print out the per-protocol part of the tuple. */
66 static int udp_print_tuple(struct seq_file *s,
67 const struct nf_conntrack_tuple *tuple)
69 return seq_printf(s, "sport=%hu dport=%hu ",
70 ntohs(tuple->src.u.udp.port),
71 ntohs(tuple->dst.u.udp.port));
74 static unsigned int *udp_get_timeouts(struct net *net)
76 return udp_pernet(net)->timeouts;
79 /* Returns verdict for packet, and may modify conntracktype */
80 static int udp_packet(struct nf_conn *ct,
81 const struct sk_buff *skb,
83 enum ip_conntrack_info ctinfo,
86 unsigned int *timeouts)
88 /* If we've seen traffic both ways, this is some kind of UDP
89 stream. Extend timeout. */
90 if (test_bit(IPS_SEEN_REPLY_BIT, &ct->status)) {
91 nf_ct_refresh_acct(ct, ctinfo, skb,
92 timeouts[UDP_CT_REPLIED]);
93 /* Also, more likely to be important, and not a probe */
94 if (!test_and_set_bit(IPS_ASSURED_BIT, &ct->status))
95 nf_conntrack_event_cache(IPCT_ASSURED, ct);
97 nf_ct_refresh_acct(ct, ctinfo, skb,
98 timeouts[UDP_CT_UNREPLIED]);
103 /* Called when a new connection for this protocol found. */
104 static bool udp_new(struct nf_conn *ct, const struct sk_buff *skb,
105 unsigned int dataoff, unsigned int *timeouts)
110 static int udp_error(struct net *net, struct nf_conn *tmpl, struct sk_buff *skb,
111 unsigned int dataoff, enum ip_conntrack_info *ctinfo,
113 unsigned int hooknum)
115 unsigned int udplen = skb->len - dataoff;
116 const struct udphdr *hdr;
119 /* Header is too small? */
120 hdr = skb_header_pointer(skb, dataoff, sizeof(_hdr), &_hdr);
122 if (LOG_INVALID(net, IPPROTO_UDP))
123 nf_log_packet(net, pf, 0, skb, NULL, NULL, NULL,
124 "nf_ct_udp: short packet ");
128 /* Truncated/malformed packets */
129 if (ntohs(hdr->len) > udplen || ntohs(hdr->len) < sizeof(*hdr)) {
130 if (LOG_INVALID(net, IPPROTO_UDP))
131 nf_log_packet(net, pf, 0, skb, NULL, NULL, NULL,
132 "nf_ct_udp: truncated/malformed packet ");
136 /* Packet with no checksum */
140 /* Checksum invalid? Ignore.
141 * We skip checking packets on the outgoing path
142 * because the checksum is assumed to be correct.
143 * FIXME: Source route IP option packets --RR */
144 if (net->ct.sysctl_checksum && hooknum == NF_INET_PRE_ROUTING &&
145 nf_checksum(skb, hooknum, dataoff, IPPROTO_UDP, pf)) {
146 if (LOG_INVALID(net, IPPROTO_UDP))
147 nf_log_packet(net, pf, 0, skb, NULL, NULL, NULL,
148 "nf_ct_udp: bad UDP checksum ");
155 #if IS_ENABLED(CONFIG_NF_CT_NETLINK_TIMEOUT)
157 #include <linux/netfilter/nfnetlink.h>
158 #include <linux/netfilter/nfnetlink_cttimeout.h>
160 static int udp_timeout_nlattr_to_obj(struct nlattr *tb[],
161 struct net *net, void *data)
163 unsigned int *timeouts = data;
164 struct nf_udp_net *un = udp_pernet(net);
166 /* set default timeouts for UDP. */
167 timeouts[UDP_CT_UNREPLIED] = un->timeouts[UDP_CT_UNREPLIED];
168 timeouts[UDP_CT_REPLIED] = un->timeouts[UDP_CT_REPLIED];
170 if (tb[CTA_TIMEOUT_UDP_UNREPLIED]) {
171 timeouts[UDP_CT_UNREPLIED] =
172 ntohl(nla_get_be32(tb[CTA_TIMEOUT_UDP_UNREPLIED])) * HZ;
174 if (tb[CTA_TIMEOUT_UDP_REPLIED]) {
175 timeouts[UDP_CT_REPLIED] =
176 ntohl(nla_get_be32(tb[CTA_TIMEOUT_UDP_REPLIED])) * HZ;
182 udp_timeout_obj_to_nlattr(struct sk_buff *skb, const void *data)
184 const unsigned int *timeouts = data;
186 if (nla_put_be32(skb, CTA_TIMEOUT_UDP_UNREPLIED,
187 htonl(timeouts[UDP_CT_UNREPLIED] / HZ)) ||
188 nla_put_be32(skb, CTA_TIMEOUT_UDP_REPLIED,
189 htonl(timeouts[UDP_CT_REPLIED] / HZ)))
190 goto nla_put_failure;
197 static const struct nla_policy
198 udp_timeout_nla_policy[CTA_TIMEOUT_UDP_MAX+1] = {
199 [CTA_TIMEOUT_UDP_UNREPLIED] = { .type = NLA_U32 },
200 [CTA_TIMEOUT_UDP_REPLIED] = { .type = NLA_U32 },
202 #endif /* CONFIG_NF_CT_NETLINK_TIMEOUT */
205 static struct ctl_table udp_sysctl_table[] = {
207 .procname = "nf_conntrack_udp_timeout",
208 .maxlen = sizeof(unsigned int),
210 .proc_handler = proc_dointvec_jiffies,
213 .procname = "nf_conntrack_udp_timeout_stream",
214 .maxlen = sizeof(unsigned int),
216 .proc_handler = proc_dointvec_jiffies,
220 #ifdef CONFIG_NF_CONNTRACK_PROC_COMPAT
221 static struct ctl_table udp_compat_sysctl_table[] = {
223 .procname = "ip_conntrack_udp_timeout",
224 .maxlen = sizeof(unsigned int),
226 .proc_handler = proc_dointvec_jiffies,
229 .procname = "ip_conntrack_udp_timeout_stream",
230 .maxlen = sizeof(unsigned int),
232 .proc_handler = proc_dointvec_jiffies,
236 #endif /* CONFIG_NF_CONNTRACK_PROC_COMPAT */
237 #endif /* CONFIG_SYSCTL */
239 static int udp_kmemdup_sysctl_table(struct nf_proto_net *pn,
240 struct nf_udp_net *un)
245 pn->ctl_table = kmemdup(udp_sysctl_table,
246 sizeof(udp_sysctl_table),
250 pn->ctl_table[0].data = &un->timeouts[UDP_CT_UNREPLIED];
251 pn->ctl_table[1].data = &un->timeouts[UDP_CT_REPLIED];
256 static int udp_kmemdup_compat_sysctl_table(struct nf_proto_net *pn,
257 struct nf_udp_net *un)
260 #ifdef CONFIG_NF_CONNTRACK_PROC_COMPAT
261 pn->ctl_compat_table = kmemdup(udp_compat_sysctl_table,
262 sizeof(udp_compat_sysctl_table),
264 if (!pn->ctl_compat_table)
267 pn->ctl_compat_table[0].data = &un->timeouts[UDP_CT_UNREPLIED];
268 pn->ctl_compat_table[1].data = &un->timeouts[UDP_CT_REPLIED];
274 static int udp_init_net(struct net *net, u_int16_t proto)
277 struct nf_udp_net *un = udp_pernet(net);
278 struct nf_proto_net *pn = &un->pn;
283 for (i = 0; i < UDP_CT_MAX; i++)
284 un->timeouts[i] = udp_timeouts[i];
287 if (proto == AF_INET) {
288 ret = udp_kmemdup_compat_sysctl_table(pn, un);
292 ret = udp_kmemdup_sysctl_table(pn, un);
294 nf_ct_kfree_compat_sysctl_table(pn);
296 ret = udp_kmemdup_sysctl_table(pn, un);
301 static struct nf_proto_net *udp_get_net_proto(struct net *net)
303 return &net->ct.nf_ct_proto.udp.pn;
306 struct nf_conntrack_l4proto nf_conntrack_l4proto_udp4 __read_mostly =
309 .l4proto = IPPROTO_UDP,
311 .pkt_to_tuple = udp_pkt_to_tuple,
312 .invert_tuple = udp_invert_tuple,
313 .print_tuple = udp_print_tuple,
314 .packet = udp_packet,
315 .get_timeouts = udp_get_timeouts,
318 #if IS_ENABLED(CONFIG_NF_CT_NETLINK)
319 .tuple_to_nlattr = nf_ct_port_tuple_to_nlattr,
320 .nlattr_to_tuple = nf_ct_port_nlattr_to_tuple,
321 .nlattr_tuple_size = nf_ct_port_nlattr_tuple_size,
322 .nla_policy = nf_ct_port_nla_policy,
324 #if IS_ENABLED(CONFIG_NF_CT_NETLINK_TIMEOUT)
326 .nlattr_to_obj = udp_timeout_nlattr_to_obj,
327 .obj_to_nlattr = udp_timeout_obj_to_nlattr,
328 .nlattr_max = CTA_TIMEOUT_UDP_MAX,
329 .obj_size = sizeof(unsigned int) * CTA_TIMEOUT_UDP_MAX,
330 .nla_policy = udp_timeout_nla_policy,
332 #endif /* CONFIG_NF_CT_NETLINK_TIMEOUT */
333 .init_net = udp_init_net,
334 .get_net_proto = udp_get_net_proto,
336 EXPORT_SYMBOL_GPL(nf_conntrack_l4proto_udp4);
338 struct nf_conntrack_l4proto nf_conntrack_l4proto_udp6 __read_mostly =
341 .l4proto = IPPROTO_UDP,
343 .pkt_to_tuple = udp_pkt_to_tuple,
344 .invert_tuple = udp_invert_tuple,
345 .print_tuple = udp_print_tuple,
346 .packet = udp_packet,
347 .get_timeouts = udp_get_timeouts,
350 #if IS_ENABLED(CONFIG_NF_CT_NETLINK)
351 .tuple_to_nlattr = nf_ct_port_tuple_to_nlattr,
352 .nlattr_to_tuple = nf_ct_port_nlattr_to_tuple,
353 .nlattr_tuple_size = nf_ct_port_nlattr_tuple_size,
354 .nla_policy = nf_ct_port_nla_policy,
356 #if IS_ENABLED(CONFIG_NF_CT_NETLINK_TIMEOUT)
358 .nlattr_to_obj = udp_timeout_nlattr_to_obj,
359 .obj_to_nlattr = udp_timeout_obj_to_nlattr,
360 .nlattr_max = CTA_TIMEOUT_UDP_MAX,
361 .obj_size = sizeof(unsigned int) * CTA_TIMEOUT_UDP_MAX,
362 .nla_policy = udp_timeout_nla_policy,
364 #endif /* CONFIG_NF_CT_NETLINK_TIMEOUT */
365 .init_net = udp_init_net,
366 .get_net_proto = udp_get_net_proto,
368 EXPORT_SYMBOL_GPL(nf_conntrack_l4proto_udp6);