1 // SPDX-License-Identifier: GPL-2.0-only
2 /* (C) 1999-2001 Paul `Rusty' Russell
3 * (C) 2002-2004 Netfilter Core Team <coreteam@netfilter.org>
4 * (C) 2006-2012 Patrick McHardy <kaber@trash.net>
7 #include <linux/types.h>
8 #include <linux/timer.h>
9 #include <linux/module.h>
10 #include <linux/udp.h>
11 #include <linux/seq_file.h>
12 #include <linux/skbuff.h>
13 #include <linux/ipv6.h>
14 #include <net/ip6_checksum.h>
15 #include <net/checksum.h>
17 #include <linux/netfilter.h>
18 #include <linux/netfilter_ipv4.h>
19 #include <linux/netfilter_ipv6.h>
20 #include <net/netfilter/nf_conntrack_l4proto.h>
21 #include <net/netfilter/nf_conntrack_ecache.h>
22 #include <net/netfilter/nf_conntrack_timeout.h>
23 #include <net/netfilter/nf_log.h>
24 #include <net/netfilter/ipv4/nf_conntrack_ipv4.h>
25 #include <net/netfilter/ipv6/nf_conntrack_ipv6.h>
27 static const unsigned int udp_timeouts[UDP_CT_MAX] = {
28 [UDP_CT_UNREPLIED] = 30*HZ,
29 [UDP_CT_REPLIED] = 120*HZ,
32 static unsigned int *udp_get_timeouts(struct net *net)
34 return nf_udp_pernet(net)->timeouts;
37 static void udp_error_log(const struct sk_buff *skb,
38 const struct nf_hook_state *state,
41 nf_l4proto_log_invalid(skb, state, IPPROTO_UDP, "%s", msg);
44 static bool udp_error(struct sk_buff *skb,
46 const struct nf_hook_state *state)
48 unsigned int udplen = skb->len - dataoff;
49 const struct udphdr *hdr;
52 /* Header is too small? */
53 hdr = skb_header_pointer(skb, dataoff, sizeof(_hdr), &_hdr);
55 udp_error_log(skb, state, "short packet");
59 /* Truncated/malformed packets */
60 if (ntohs(hdr->len) > udplen || ntohs(hdr->len) < sizeof(*hdr)) {
61 udp_error_log(skb, state, "truncated/malformed packet");
65 /* Packet with no checksum */
69 /* Checksum invalid? Ignore.
70 * We skip checking packets on the outgoing path
71 * because the checksum is assumed to be correct.
72 * FIXME: Source route IP option packets --RR */
73 if (state->hook == NF_INET_PRE_ROUTING &&
74 state->net->ct.sysctl_checksum &&
75 nf_checksum(skb, state->hook, dataoff, IPPROTO_UDP, state->pf)) {
76 udp_error_log(skb, state, "bad checksum");
83 /* Returns verdict for packet, and may modify conntracktype */
84 int nf_conntrack_udp_packet(struct nf_conn *ct,
87 enum ip_conntrack_info ctinfo,
88 const struct nf_hook_state *state)
90 unsigned int *timeouts;
92 if (udp_error(skb, dataoff, state))
95 timeouts = nf_ct_timeout_lookup(ct);
97 timeouts = udp_get_timeouts(nf_ct_net(ct));
99 if (!nf_ct_is_confirmed(ct))
100 ct->proto.udp.stream_ts = 2 * HZ + jiffies;
102 /* If we've seen traffic both ways, this is some kind of UDP
103 * stream. Set Assured.
105 if (test_bit(IPS_SEEN_REPLY_BIT, &ct->status)) {
106 unsigned long extra = timeouts[UDP_CT_UNREPLIED];
108 /* Still active after two seconds? Extend timeout. */
109 if (time_after(jiffies, ct->proto.udp.stream_ts))
110 extra = timeouts[UDP_CT_REPLIED];
112 nf_ct_refresh_acct(ct, ctinfo, skb, extra);
114 /* never set ASSURED for IPS_NAT_CLASH, they time out soon */
115 if (unlikely((ct->status & IPS_NAT_CLASH)))
118 /* Also, more likely to be important, and not a probe */
119 if (!test_and_set_bit(IPS_ASSURED_BIT, &ct->status))
120 nf_conntrack_event_cache(IPCT_ASSURED, ct);
122 nf_ct_refresh_acct(ct, ctinfo, skb, timeouts[UDP_CT_UNREPLIED]);
127 #ifdef CONFIG_NF_CT_PROTO_UDPLITE
128 static void udplite_error_log(const struct sk_buff *skb,
129 const struct nf_hook_state *state,
132 nf_l4proto_log_invalid(skb, state, IPPROTO_UDPLITE, "%s", msg);
135 static bool udplite_error(struct sk_buff *skb,
136 unsigned int dataoff,
137 const struct nf_hook_state *state)
139 unsigned int udplen = skb->len - dataoff;
140 const struct udphdr *hdr;
144 /* Header is too small? */
145 hdr = skb_header_pointer(skb, dataoff, sizeof(_hdr), &_hdr);
147 udplite_error_log(skb, state, "short packet");
151 cscov = ntohs(hdr->len);
154 } else if (cscov < sizeof(*hdr) || cscov > udplen) {
155 udplite_error_log(skb, state, "invalid checksum coverage");
159 /* UDPLITE mandates checksums */
161 udplite_error_log(skb, state, "checksum missing");
165 /* Checksum invalid? Ignore. */
166 if (state->hook == NF_INET_PRE_ROUTING &&
167 state->net->ct.sysctl_checksum &&
168 nf_checksum_partial(skb, state->hook, dataoff, cscov, IPPROTO_UDP,
170 udplite_error_log(skb, state, "bad checksum");
177 /* Returns verdict for packet, and may modify conntracktype */
178 int nf_conntrack_udplite_packet(struct nf_conn *ct,
180 unsigned int dataoff,
181 enum ip_conntrack_info ctinfo,
182 const struct nf_hook_state *state)
184 unsigned int *timeouts;
186 if (udplite_error(skb, dataoff, state))
189 timeouts = nf_ct_timeout_lookup(ct);
191 timeouts = udp_get_timeouts(nf_ct_net(ct));
193 /* If we've seen traffic both ways, this is some kind of UDP
194 stream. Extend timeout. */
195 if (test_bit(IPS_SEEN_REPLY_BIT, &ct->status)) {
196 nf_ct_refresh_acct(ct, ctinfo, skb,
197 timeouts[UDP_CT_REPLIED]);
199 if (unlikely((ct->status & IPS_NAT_CLASH)))
202 /* Also, more likely to be important, and not a probe */
203 if (!test_and_set_bit(IPS_ASSURED_BIT, &ct->status))
204 nf_conntrack_event_cache(IPCT_ASSURED, ct);
206 nf_ct_refresh_acct(ct, ctinfo, skb, timeouts[UDP_CT_UNREPLIED]);
212 #ifdef CONFIG_NF_CONNTRACK_TIMEOUT
214 #include <linux/netfilter/nfnetlink.h>
215 #include <linux/netfilter/nfnetlink_cttimeout.h>
217 static int udp_timeout_nlattr_to_obj(struct nlattr *tb[],
218 struct net *net, void *data)
220 unsigned int *timeouts = data;
221 struct nf_udp_net *un = nf_udp_pernet(net);
224 timeouts = un->timeouts;
226 /* set default timeouts for UDP. */
227 timeouts[UDP_CT_UNREPLIED] = un->timeouts[UDP_CT_UNREPLIED];
228 timeouts[UDP_CT_REPLIED] = un->timeouts[UDP_CT_REPLIED];
230 if (tb[CTA_TIMEOUT_UDP_UNREPLIED]) {
231 timeouts[UDP_CT_UNREPLIED] =
232 ntohl(nla_get_be32(tb[CTA_TIMEOUT_UDP_UNREPLIED])) * HZ;
234 if (tb[CTA_TIMEOUT_UDP_REPLIED]) {
235 timeouts[UDP_CT_REPLIED] =
236 ntohl(nla_get_be32(tb[CTA_TIMEOUT_UDP_REPLIED])) * HZ;
242 udp_timeout_obj_to_nlattr(struct sk_buff *skb, const void *data)
244 const unsigned int *timeouts = data;
246 if (nla_put_be32(skb, CTA_TIMEOUT_UDP_UNREPLIED,
247 htonl(timeouts[UDP_CT_UNREPLIED] / HZ)) ||
248 nla_put_be32(skb, CTA_TIMEOUT_UDP_REPLIED,
249 htonl(timeouts[UDP_CT_REPLIED] / HZ)))
250 goto nla_put_failure;
257 static const struct nla_policy
258 udp_timeout_nla_policy[CTA_TIMEOUT_UDP_MAX+1] = {
259 [CTA_TIMEOUT_UDP_UNREPLIED] = { .type = NLA_U32 },
260 [CTA_TIMEOUT_UDP_REPLIED] = { .type = NLA_U32 },
262 #endif /* CONFIG_NF_CONNTRACK_TIMEOUT */
264 void nf_conntrack_udp_init_net(struct net *net)
266 struct nf_udp_net *un = nf_udp_pernet(net);
269 for (i = 0; i < UDP_CT_MAX; i++)
270 un->timeouts[i] = udp_timeouts[i];
272 #if IS_ENABLED(CONFIG_NF_FLOW_TABLE)
273 un->offload_timeout = 30 * HZ;
274 un->offload_pickup = 30 * HZ;
278 const struct nf_conntrack_l4proto nf_conntrack_l4proto_udp =
280 .l4proto = IPPROTO_UDP,
282 #if IS_ENABLED(CONFIG_NF_CT_NETLINK)
283 .tuple_to_nlattr = nf_ct_port_tuple_to_nlattr,
284 .nlattr_to_tuple = nf_ct_port_nlattr_to_tuple,
285 .nlattr_tuple_size = nf_ct_port_nlattr_tuple_size,
286 .nla_policy = nf_ct_port_nla_policy,
288 #ifdef CONFIG_NF_CONNTRACK_TIMEOUT
290 .nlattr_to_obj = udp_timeout_nlattr_to_obj,
291 .obj_to_nlattr = udp_timeout_obj_to_nlattr,
292 .nlattr_max = CTA_TIMEOUT_UDP_MAX,
293 .obj_size = sizeof(unsigned int) * CTA_TIMEOUT_UDP_MAX,
294 .nla_policy = udp_timeout_nla_policy,
296 #endif /* CONFIG_NF_CONNTRACK_TIMEOUT */
299 #ifdef CONFIG_NF_CT_PROTO_UDPLITE
300 const struct nf_conntrack_l4proto nf_conntrack_l4proto_udplite =
302 .l4proto = IPPROTO_UDPLITE,
304 #if IS_ENABLED(CONFIG_NF_CT_NETLINK)
305 .tuple_to_nlattr = nf_ct_port_tuple_to_nlattr,
306 .nlattr_to_tuple = nf_ct_port_nlattr_to_tuple,
307 .nlattr_tuple_size = nf_ct_port_nlattr_tuple_size,
308 .nla_policy = nf_ct_port_nla_policy,
310 #ifdef CONFIG_NF_CONNTRACK_TIMEOUT
312 .nlattr_to_obj = udp_timeout_nlattr_to_obj,
313 .obj_to_nlattr = udp_timeout_obj_to_nlattr,
314 .nlattr_max = CTA_TIMEOUT_UDP_MAX,
315 .obj_size = sizeof(unsigned int) * CTA_TIMEOUT_UDP_MAX,
316 .nla_policy = udp_timeout_nla_policy,
318 #endif /* CONFIG_NF_CONNTRACK_TIMEOUT */