Commit | Line | Data |
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d2912cb1 | 1 | // SPDX-License-Identifier: GPL-2.0-only |
9fb9cbb1 YK |
2 | /* (C) 1999-2001 Paul `Rusty' Russell |
3 | * (C) 2002-2004 Netfilter Core Team <coreteam@netfilter.org> | |
f229f6ce | 4 | * (C) 2006-2012 Patrick McHardy <kaber@trash.net> |
9fb9cbb1 YK |
5 | */ |
6 | ||
7 | #include <linux/types.h> | |
9fb9cbb1 YK |
8 | #include <linux/timer.h> |
9 | #include <linux/module.h> | |
9fb9cbb1 YK |
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> | |
f6180121 | 16 | |
9fb9cbb1 YK |
17 | #include <linux/netfilter.h> |
18 | #include <linux/netfilter_ipv4.h> | |
19 | #include <linux/netfilter_ipv6.h> | |
605dcad6 | 20 | #include <net/netfilter/nf_conntrack_l4proto.h> |
f6180121 | 21 | #include <net/netfilter/nf_conntrack_ecache.h> |
c779e849 | 22 | #include <net/netfilter/nf_conntrack_timeout.h> |
f01ffbd6 | 23 | #include <net/netfilter/nf_log.h> |
9d2493f8 CP |
24 | #include <net/netfilter/ipv4/nf_conntrack_ipv4.h> |
25 | #include <net/netfilter/ipv6/nf_conntrack_ipv6.h> | |
9fb9cbb1 | 26 | |
2c9e8637 | 27 | static const unsigned int udp_timeouts[UDP_CT_MAX] = { |
5a41db94 | 28 | [UDP_CT_UNREPLIED] = 30*HZ, |
294304e4 | 29 | [UDP_CT_REPLIED] = 120*HZ, |
5a41db94 | 30 | }; |
9fb9cbb1 | 31 | |
2c8503f5 PNA |
32 | static unsigned int *udp_get_timeouts(struct net *net) |
33 | { | |
a95a7774 | 34 | return nf_udp_pernet(net)->timeouts; |
2c8503f5 PNA |
35 | } |
36 | ||
83d213fd FW |
37 | static void udp_error_log(const struct sk_buff *skb, |
38 | const struct nf_hook_state *state, | |
39 | const char *msg) | |
40 | { | |
41 | nf_l4proto_log_invalid(skb, state->net, state->pf, | |
42 | IPPROTO_UDP, "%s", msg); | |
43 | } | |
44 | ||
45 | static bool udp_error(struct sk_buff *skb, | |
46 | unsigned int dataoff, | |
47 | const struct nf_hook_state *state) | |
48 | { | |
49 | unsigned int udplen = skb->len - dataoff; | |
50 | const struct udphdr *hdr; | |
51 | struct udphdr _hdr; | |
52 | ||
53 | /* Header is too small? */ | |
54 | hdr = skb_header_pointer(skb, dataoff, sizeof(_hdr), &_hdr); | |
55 | if (!hdr) { | |
56 | udp_error_log(skb, state, "short packet"); | |
57 | return true; | |
58 | } | |
59 | ||
60 | /* Truncated/malformed packets */ | |
61 | if (ntohs(hdr->len) > udplen || ntohs(hdr->len) < sizeof(*hdr)) { | |
62 | udp_error_log(skb, state, "truncated/malformed packet"); | |
63 | return true; | |
64 | } | |
65 | ||
66 | /* Packet with no checksum */ | |
67 | if (!hdr->check) | |
68 | return false; | |
69 | ||
70 | /* Checksum invalid? Ignore. | |
71 | * We skip checking packets on the outgoing path | |
72 | * because the checksum is assumed to be correct. | |
73 | * FIXME: Source route IP option packets --RR */ | |
74 | if (state->hook == NF_INET_PRE_ROUTING && | |
75 | state->net->ct.sysctl_checksum && | |
76 | nf_checksum(skb, state->hook, dataoff, IPPROTO_UDP, state->pf)) { | |
77 | udp_error_log(skb, state, "bad checksum"); | |
78 | return true; | |
79 | } | |
80 | ||
81 | return false; | |
82 | } | |
83 | ||
9fb9cbb1 | 84 | /* Returns verdict for packet, and may modify conntracktype */ |
a47c5404 FW |
85 | int nf_conntrack_udp_packet(struct nf_conn *ct, |
86 | struct sk_buff *skb, | |
87 | unsigned int dataoff, | |
88 | enum ip_conntrack_info ctinfo, | |
89 | const struct nf_hook_state *state) | |
9fb9cbb1 | 90 | { |
c779e849 FW |
91 | unsigned int *timeouts; |
92 | ||
83d213fd FW |
93 | if (udp_error(skb, dataoff, state)) |
94 | return -NF_ACCEPT; | |
95 | ||
c779e849 FW |
96 | timeouts = nf_ct_timeout_lookup(ct); |
97 | if (!timeouts) | |
98 | timeouts = udp_get_timeouts(nf_ct_net(ct)); | |
99 | ||
d535c8a6 FW |
100 | if (!nf_ct_is_confirmed(ct)) |
101 | ct->proto.udp.stream_ts = 2 * HZ + jiffies; | |
102 | ||
9fb9cbb1 | 103 | /* If we've seen traffic both ways, this is some kind of UDP |
d535c8a6 FW |
104 | * stream. Set Assured. |
105 | */ | |
c88130bc | 106 | if (test_bit(IPS_SEEN_REPLY_BIT, &ct->status)) { |
d535c8a6 FW |
107 | unsigned long extra = timeouts[UDP_CT_UNREPLIED]; |
108 | ||
109 | /* Still active after two seconds? Extend timeout. */ | |
110 | if (time_after(jiffies, ct->proto.udp.stream_ts)) | |
111 | extra = timeouts[UDP_CT_REPLIED]; | |
112 | ||
113 | nf_ct_refresh_acct(ct, ctinfo, skb, extra); | |
114 | ||
9fb9cbb1 | 115 | /* Also, more likely to be important, and not a probe */ |
c88130bc | 116 | if (!test_and_set_bit(IPS_ASSURED_BIT, &ct->status)) |
858b3133 | 117 | nf_conntrack_event_cache(IPCT_ASSURED, ct); |
5a41db94 PNA |
118 | } else { |
119 | nf_ct_refresh_acct(ct, ctinfo, skb, | |
2c8503f5 | 120 | timeouts[UDP_CT_UNREPLIED]); |
5a41db94 | 121 | } |
9fb9cbb1 YK |
122 | return NF_ACCEPT; |
123 | } | |
124 | ||
e4781421 | 125 | #ifdef CONFIG_NF_CT_PROTO_UDPLITE |
93e66024 FW |
126 | static void udplite_error_log(const struct sk_buff *skb, |
127 | const struct nf_hook_state *state, | |
128 | const char *msg) | |
c4f3db15 | 129 | { |
93e66024 FW |
130 | nf_l4proto_log_invalid(skb, state->net, state->pf, |
131 | IPPROTO_UDPLITE, "%s", msg); | |
c4f3db15 FW |
132 | } |
133 | ||
83d213fd FW |
134 | static bool udplite_error(struct sk_buff *skb, |
135 | unsigned int dataoff, | |
136 | const struct nf_hook_state *state) | |
e4781421 FW |
137 | { |
138 | unsigned int udplen = skb->len - dataoff; | |
139 | const struct udphdr *hdr; | |
140 | struct udphdr _hdr; | |
141 | unsigned int cscov; | |
142 | ||
143 | /* Header is too small? */ | |
144 | hdr = skb_header_pointer(skb, dataoff, sizeof(_hdr), &_hdr); | |
145 | if (!hdr) { | |
93e66024 | 146 | udplite_error_log(skb, state, "short packet"); |
83d213fd | 147 | return true; |
e4781421 FW |
148 | } |
149 | ||
150 | cscov = ntohs(hdr->len); | |
151 | if (cscov == 0) { | |
152 | cscov = udplen; | |
153 | } else if (cscov < sizeof(*hdr) || cscov > udplen) { | |
93e66024 | 154 | udplite_error_log(skb, state, "invalid checksum coverage"); |
83d213fd | 155 | return true; |
e4781421 FW |
156 | } |
157 | ||
158 | /* UDPLITE mandates checksums */ | |
159 | if (!hdr->check) { | |
93e66024 | 160 | udplite_error_log(skb, state, "checksum missing"); |
83d213fd | 161 | return true; |
e4781421 FW |
162 | } |
163 | ||
164 | /* Checksum invalid? Ignore. */ | |
93e66024 FW |
165 | if (state->hook == NF_INET_PRE_ROUTING && |
166 | state->net->ct.sysctl_checksum && | |
167 | nf_checksum_partial(skb, state->hook, dataoff, cscov, IPPROTO_UDP, | |
168 | state->pf)) { | |
169 | udplite_error_log(skb, state, "bad checksum"); | |
83d213fd | 170 | return true; |
e4781421 FW |
171 | } |
172 | ||
83d213fd | 173 | return false; |
e4781421 | 174 | } |
e4781421 | 175 | |
83d213fd | 176 | /* Returns verdict for packet, and may modify conntracktype */ |
a47c5404 FW |
177 | int nf_conntrack_udplite_packet(struct nf_conn *ct, |
178 | struct sk_buff *skb, | |
179 | unsigned int dataoff, | |
180 | enum ip_conntrack_info ctinfo, | |
181 | const struct nf_hook_state *state) | |
9fb9cbb1 | 182 | { |
83d213fd | 183 | unsigned int *timeouts; |
9fb9cbb1 | 184 | |
83d213fd | 185 | if (udplite_error(skb, dataoff, state)) |
9fb9cbb1 | 186 | return -NF_ACCEPT; |
9fb9cbb1 | 187 | |
83d213fd FW |
188 | timeouts = nf_ct_timeout_lookup(ct); |
189 | if (!timeouts) | |
190 | timeouts = udp_get_timeouts(nf_ct_net(ct)); | |
9fb9cbb1 | 191 | |
83d213fd FW |
192 | /* If we've seen traffic both ways, this is some kind of UDP |
193 | stream. Extend timeout. */ | |
194 | if (test_bit(IPS_SEEN_REPLY_BIT, &ct->status)) { | |
195 | nf_ct_refresh_acct(ct, ctinfo, skb, | |
196 | timeouts[UDP_CT_REPLIED]); | |
197 | /* Also, more likely to be important, and not a probe */ | |
198 | if (!test_and_set_bit(IPS_ASSURED_BIT, &ct->status)) | |
199 | nf_conntrack_event_cache(IPCT_ASSURED, ct); | |
200 | } else { | |
201 | nf_ct_refresh_acct(ct, ctinfo, skb, | |
202 | timeouts[UDP_CT_UNREPLIED]); | |
9fb9cbb1 | 203 | } |
9fb9cbb1 YK |
204 | return NF_ACCEPT; |
205 | } | |
83d213fd | 206 | #endif |
9fb9cbb1 | 207 | |
a874752a | 208 | #ifdef CONFIG_NF_CONNTRACK_TIMEOUT |
50978462 PNA |
209 | |
210 | #include <linux/netfilter/nfnetlink.h> | |
211 | #include <linux/netfilter/nfnetlink_cttimeout.h> | |
212 | ||
8264deb8 G |
213 | static int udp_timeout_nlattr_to_obj(struct nlattr *tb[], |
214 | struct net *net, void *data) | |
50978462 PNA |
215 | { |
216 | unsigned int *timeouts = data; | |
a95a7774 | 217 | struct nf_udp_net *un = nf_udp_pernet(net); |
50978462 | 218 | |
c779e849 FW |
219 | if (!timeouts) |
220 | timeouts = un->timeouts; | |
221 | ||
50978462 | 222 | /* set default timeouts for UDP. */ |
8264deb8 G |
223 | timeouts[UDP_CT_UNREPLIED] = un->timeouts[UDP_CT_UNREPLIED]; |
224 | timeouts[UDP_CT_REPLIED] = un->timeouts[UDP_CT_REPLIED]; | |
50978462 PNA |
225 | |
226 | if (tb[CTA_TIMEOUT_UDP_UNREPLIED]) { | |
227 | timeouts[UDP_CT_UNREPLIED] = | |
228 | ntohl(nla_get_be32(tb[CTA_TIMEOUT_UDP_UNREPLIED])) * HZ; | |
229 | } | |
230 | if (tb[CTA_TIMEOUT_UDP_REPLIED]) { | |
231 | timeouts[UDP_CT_REPLIED] = | |
232 | ntohl(nla_get_be32(tb[CTA_TIMEOUT_UDP_REPLIED])) * HZ; | |
233 | } | |
234 | return 0; | |
235 | } | |
236 | ||
237 | static int | |
238 | udp_timeout_obj_to_nlattr(struct sk_buff *skb, const void *data) | |
239 | { | |
240 | const unsigned int *timeouts = data; | |
241 | ||
3c60a17b DM |
242 | if (nla_put_be32(skb, CTA_TIMEOUT_UDP_UNREPLIED, |
243 | htonl(timeouts[UDP_CT_UNREPLIED] / HZ)) || | |
244 | nla_put_be32(skb, CTA_TIMEOUT_UDP_REPLIED, | |
245 | htonl(timeouts[UDP_CT_REPLIED] / HZ))) | |
246 | goto nla_put_failure; | |
50978462 PNA |
247 | return 0; |
248 | ||
249 | nla_put_failure: | |
250 | return -ENOSPC; | |
251 | } | |
252 | ||
253 | static const struct nla_policy | |
254 | udp_timeout_nla_policy[CTA_TIMEOUT_UDP_MAX+1] = { | |
255 | [CTA_TIMEOUT_UDP_UNREPLIED] = { .type = NLA_U32 }, | |
256 | [CTA_TIMEOUT_UDP_REPLIED] = { .type = NLA_U32 }, | |
257 | }; | |
a874752a | 258 | #endif /* CONFIG_NF_CONNTRACK_TIMEOUT */ |
50978462 | 259 | |
2a389de8 | 260 | void nf_conntrack_udp_init_net(struct net *net) |
0ce490ad | 261 | { |
a95a7774 | 262 | struct nf_udp_net *un = nf_udp_pernet(net); |
2a389de8 | 263 | int i; |
0ce490ad | 264 | |
2a389de8 FW |
265 | for (i = 0; i < UDP_CT_MAX; i++) |
266 | un->timeouts[i] = udp_timeouts[i]; | |
08911475 PNA |
267 | } |
268 | ||
dd2934a9 | 269 | const struct nf_conntrack_l4proto nf_conntrack_l4proto_udp = |
9fb9cbb1 | 270 | { |
605dcad6 | 271 | .l4proto = IPPROTO_UDP, |
71d8c47f | 272 | .allow_clash = true, |
c0cd1156 | 273 | #if IS_ENABLED(CONFIG_NF_CT_NETLINK) |
fdf70832 PM |
274 | .tuple_to_nlattr = nf_ct_port_tuple_to_nlattr, |
275 | .nlattr_to_tuple = nf_ct_port_nlattr_to_tuple, | |
a400c30e | 276 | .nlattr_tuple_size = nf_ct_port_nlattr_tuple_size, |
f73e924c | 277 | .nla_policy = nf_ct_port_nla_policy, |
c1d10adb | 278 | #endif |
a874752a | 279 | #ifdef CONFIG_NF_CONNTRACK_TIMEOUT |
50978462 PNA |
280 | .ctnl_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, | |
286 | }, | |
a874752a | 287 | #endif /* CONFIG_NF_CONNTRACK_TIMEOUT */ |
9fb9cbb1 YK |
288 | }; |
289 | ||
e4781421 | 290 | #ifdef CONFIG_NF_CT_PROTO_UDPLITE |
dd2934a9 | 291 | const struct nf_conntrack_l4proto nf_conntrack_l4proto_udplite = |
e4781421 | 292 | { |
e4781421 | 293 | .l4proto = IPPROTO_UDPLITE, |
e4781421 | 294 | .allow_clash = true, |
e4781421 FW |
295 | #if IS_ENABLED(CONFIG_NF_CT_NETLINK) |
296 | .tuple_to_nlattr = nf_ct_port_tuple_to_nlattr, | |
297 | .nlattr_to_tuple = nf_ct_port_nlattr_to_tuple, | |
298 | .nlattr_tuple_size = nf_ct_port_nlattr_tuple_size, | |
299 | .nla_policy = nf_ct_port_nla_policy, | |
300 | #endif | |
a874752a | 301 | #ifdef CONFIG_NF_CONNTRACK_TIMEOUT |
e4781421 FW |
302 | .ctnl_timeout = { |
303 | .nlattr_to_obj = udp_timeout_nlattr_to_obj, | |
304 | .obj_to_nlattr = udp_timeout_obj_to_nlattr, | |
305 | .nlattr_max = CTA_TIMEOUT_UDP_MAX, | |
306 | .obj_size = sizeof(unsigned int) * CTA_TIMEOUT_UDP_MAX, | |
307 | .nla_policy = udp_timeout_nla_policy, | |
308 | }, | |
a874752a | 309 | #endif /* CONFIG_NF_CONNTRACK_TIMEOUT */ |
e4781421 | 310 | }; |
e4781421 | 311 | #endif |