1 /* (C) 1999-2001 Paul `Rusty' Russell
2 * (C) 2002-2004 Netfilter Core Team <coreteam@netfilter.org>
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.
9 #include <linux/types.h>
10 #include <linux/timer.h>
11 #include <linux/module.h>
12 #include <linux/udp.h>
13 #include <linux/seq_file.h>
14 #include <linux/skbuff.h>
15 #include <linux/ipv6.h>
16 #include <net/ip6_checksum.h>
17 #include <net/checksum.h>
19 #include <linux/netfilter.h>
20 #include <linux/netfilter_ipv4.h>
21 #include <linux/netfilter_ipv6.h>
22 #include <net/netfilter/nf_conntrack_l4proto.h>
23 #include <net/netfilter/nf_conntrack_ecache.h>
24 #include <net/netfilter/nf_log.h>
25 #include <net/netfilter/ipv4/nf_conntrack_ipv4.h>
26 #include <net/netfilter/ipv6/nf_conntrack_ipv6.h>
34 static unsigned int udp_timeouts[UDP_CT_MAX] = {
35 [UDP_CT_UNREPLIED] = 30*HZ,
36 [UDP_CT_REPLIED] = 180*HZ,
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)
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(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(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(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[], void *data)
162 unsigned int *timeouts = data;
164 /* set default timeouts for UDP. */
165 timeouts[UDP_CT_UNREPLIED] = udp_timeouts[UDP_CT_UNREPLIED];
166 timeouts[UDP_CT_REPLIED] = udp_timeouts[UDP_CT_REPLIED];
168 if (tb[CTA_TIMEOUT_UDP_UNREPLIED]) {
169 timeouts[UDP_CT_UNREPLIED] =
170 ntohl(nla_get_be32(tb[CTA_TIMEOUT_UDP_UNREPLIED])) * HZ;
172 if (tb[CTA_TIMEOUT_UDP_REPLIED]) {
173 timeouts[UDP_CT_REPLIED] =
174 ntohl(nla_get_be32(tb[CTA_TIMEOUT_UDP_REPLIED])) * HZ;
180 udp_timeout_obj_to_nlattr(struct sk_buff *skb, const void *data)
182 const unsigned int *timeouts = data;
184 NLA_PUT_BE32(skb, CTA_TIMEOUT_UDP_UNREPLIED,
185 htonl(timeouts[UDP_CT_UNREPLIED] / HZ));
186 NLA_PUT_BE32(skb, CTA_TIMEOUT_UDP_REPLIED,
187 htonl(timeouts[UDP_CT_REPLIED] / HZ));
194 static const struct nla_policy
195 udp_timeout_nla_policy[CTA_TIMEOUT_UDP_MAX+1] = {
196 [CTA_TIMEOUT_UDP_UNREPLIED] = { .type = NLA_U32 },
197 [CTA_TIMEOUT_UDP_REPLIED] = { .type = NLA_U32 },
199 #endif /* CONFIG_NF_CT_NETLINK_TIMEOUT */
202 static unsigned int udp_sysctl_table_users;
203 static struct ctl_table_header *udp_sysctl_header;
204 static struct ctl_table udp_sysctl_table[] = {
206 .procname = "nf_conntrack_udp_timeout",
207 .data = &udp_timeouts[UDP_CT_UNREPLIED],
208 .maxlen = sizeof(unsigned int),
210 .proc_handler = proc_dointvec_jiffies,
213 .procname = "nf_conntrack_udp_timeout_stream",
214 .data = &udp_timeouts[UDP_CT_REPLIED],
215 .maxlen = sizeof(unsigned int),
217 .proc_handler = proc_dointvec_jiffies,
221 #ifdef CONFIG_NF_CONNTRACK_PROC_COMPAT
222 static struct ctl_table udp_compat_sysctl_table[] = {
224 .procname = "ip_conntrack_udp_timeout",
225 .data = &udp_timeouts[UDP_CT_UNREPLIED],
226 .maxlen = sizeof(unsigned int),
228 .proc_handler = proc_dointvec_jiffies,
231 .procname = "ip_conntrack_udp_timeout_stream",
232 .data = &udp_timeouts[UDP_CT_REPLIED],
233 .maxlen = sizeof(unsigned int),
235 .proc_handler = proc_dointvec_jiffies,
239 #endif /* CONFIG_NF_CONNTRACK_PROC_COMPAT */
240 #endif /* CONFIG_SYSCTL */
242 struct nf_conntrack_l4proto nf_conntrack_l4proto_udp4 __read_mostly =
245 .l4proto = IPPROTO_UDP,
247 .pkt_to_tuple = udp_pkt_to_tuple,
248 .invert_tuple = udp_invert_tuple,
249 .print_tuple = udp_print_tuple,
250 .packet = udp_packet,
251 .get_timeouts = udp_get_timeouts,
254 #if IS_ENABLED(CONFIG_NF_CT_NETLINK)
255 .tuple_to_nlattr = nf_ct_port_tuple_to_nlattr,
256 .nlattr_to_tuple = nf_ct_port_nlattr_to_tuple,
257 .nlattr_tuple_size = nf_ct_port_nlattr_tuple_size,
258 .nla_policy = nf_ct_port_nla_policy,
260 #if IS_ENABLED(CONFIG_NF_CT_NETLINK_TIMEOUT)
262 .nlattr_to_obj = udp_timeout_nlattr_to_obj,
263 .obj_to_nlattr = udp_timeout_obj_to_nlattr,
264 .nlattr_max = CTA_TIMEOUT_UDP_MAX,
265 .obj_size = sizeof(unsigned int) * CTA_TIMEOUT_UDP_MAX,
266 .nla_policy = udp_timeout_nla_policy,
268 #endif /* CONFIG_NF_CT_NETLINK_TIMEOUT */
270 .ctl_table_users = &udp_sysctl_table_users,
271 .ctl_table_header = &udp_sysctl_header,
272 .ctl_table = udp_sysctl_table,
273 #ifdef CONFIG_NF_CONNTRACK_PROC_COMPAT
274 .ctl_compat_table = udp_compat_sysctl_table,
278 EXPORT_SYMBOL_GPL(nf_conntrack_l4proto_udp4);
280 struct nf_conntrack_l4proto nf_conntrack_l4proto_udp6 __read_mostly =
283 .l4proto = IPPROTO_UDP,
285 .pkt_to_tuple = udp_pkt_to_tuple,
286 .invert_tuple = udp_invert_tuple,
287 .print_tuple = udp_print_tuple,
288 .packet = udp_packet,
289 .get_timeouts = udp_get_timeouts,
292 #if IS_ENABLED(CONFIG_NF_CT_NETLINK)
293 .tuple_to_nlattr = nf_ct_port_tuple_to_nlattr,
294 .nlattr_to_tuple = nf_ct_port_nlattr_to_tuple,
295 .nlattr_tuple_size = nf_ct_port_nlattr_tuple_size,
296 .nla_policy = nf_ct_port_nla_policy,
298 #if IS_ENABLED(CONFIG_NF_CT_NETLINK_TIMEOUT)
300 .nlattr_to_obj = udp_timeout_nlattr_to_obj,
301 .obj_to_nlattr = udp_timeout_obj_to_nlattr,
302 .nlattr_max = CTA_TIMEOUT_UDP_MAX,
303 .obj_size = sizeof(unsigned int) * CTA_TIMEOUT_UDP_MAX,
304 .nla_policy = udp_timeout_nla_policy,
306 #endif /* CONFIG_NF_CT_NETLINK_TIMEOUT */
308 .ctl_table_users = &udp_sysctl_table_users,
309 .ctl_table_header = &udp_sysctl_header,
310 .ctl_table = udp_sysctl_table,
313 EXPORT_SYMBOL_GPL(nf_conntrack_l4proto_udp6);