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24ec483c KDB |
1 | // SPDX-License-Identifier: GPL-2.0+ |
2 | /* net/sched/act_ctinfo.c netfilter ctinfo connmark actions | |
3 | * | |
4 | * Copyright (c) 2019 Kevin Darbyshire-Bryant <ldir@darbyshire-bryant.me.uk> | |
5 | */ | |
6 | ||
7 | #include <linux/module.h> | |
8 | #include <linux/init.h> | |
9 | #include <linux/kernel.h> | |
10 | #include <linux/skbuff.h> | |
11 | #include <linux/rtnetlink.h> | |
12 | #include <linux/pkt_cls.h> | |
13 | #include <linux/ip.h> | |
14 | #include <linux/ipv6.h> | |
15 | #include <net/netlink.h> | |
16 | #include <net/pkt_sched.h> | |
17 | #include <net/act_api.h> | |
18 | #include <net/pkt_cls.h> | |
19 | #include <uapi/linux/tc_act/tc_ctinfo.h> | |
20 | #include <net/tc_act/tc_ctinfo.h> | |
21 | ||
22 | #include <net/netfilter/nf_conntrack.h> | |
23 | #include <net/netfilter/nf_conntrack_core.h> | |
24 | #include <net/netfilter/nf_conntrack_ecache.h> | |
25 | #include <net/netfilter/nf_conntrack_zones.h> | |
26 | ||
27 | static struct tc_action_ops act_ctinfo_ops; | |
28 | static unsigned int ctinfo_net_id; | |
29 | ||
30 | static void tcf_ctinfo_dscp_set(struct nf_conn *ct, struct tcf_ctinfo *ca, | |
31 | struct tcf_ctinfo_params *cp, | |
32 | struct sk_buff *skb, int wlen, int proto) | |
33 | { | |
34 | u8 dscp, newdscp; | |
35 | ||
36 | newdscp = (((ct->mark & cp->dscpmask) >> cp->dscpmaskshift) << 2) & | |
37 | ~INET_ECN_MASK; | |
38 | ||
39 | switch (proto) { | |
40 | case NFPROTO_IPV4: | |
41 | dscp = ipv4_get_dsfield(ip_hdr(skb)) & ~INET_ECN_MASK; | |
42 | if (dscp != newdscp) { | |
43 | if (likely(!skb_try_make_writable(skb, wlen))) { | |
44 | ipv4_change_dsfield(ip_hdr(skb), | |
45 | INET_ECN_MASK, | |
46 | newdscp); | |
47 | ca->stats_dscp_set++; | |
48 | } else { | |
49 | ca->stats_dscp_error++; | |
50 | } | |
51 | } | |
52 | break; | |
53 | case NFPROTO_IPV6: | |
54 | dscp = ipv6_get_dsfield(ipv6_hdr(skb)) & ~INET_ECN_MASK; | |
55 | if (dscp != newdscp) { | |
56 | if (likely(!skb_try_make_writable(skb, wlen))) { | |
57 | ipv6_change_dsfield(ipv6_hdr(skb), | |
58 | INET_ECN_MASK, | |
59 | newdscp); | |
60 | ca->stats_dscp_set++; | |
61 | } else { | |
62 | ca->stats_dscp_error++; | |
63 | } | |
64 | } | |
65 | break; | |
66 | default: | |
67 | break; | |
68 | } | |
69 | } | |
70 | ||
71 | static void tcf_ctinfo_cpmark_set(struct nf_conn *ct, struct tcf_ctinfo *ca, | |
72 | struct tcf_ctinfo_params *cp, | |
73 | struct sk_buff *skb) | |
74 | { | |
75 | ca->stats_cpmark_set++; | |
76 | skb->mark = ct->mark & cp->cpmarkmask; | |
77 | } | |
78 | ||
79 | static int tcf_ctinfo_act(struct sk_buff *skb, const struct tc_action *a, | |
80 | struct tcf_result *res) | |
81 | { | |
82 | const struct nf_conntrack_tuple_hash *thash = NULL; | |
83 | struct tcf_ctinfo *ca = to_ctinfo(a); | |
84 | struct nf_conntrack_tuple tuple; | |
85 | struct nf_conntrack_zone zone; | |
86 | enum ip_conntrack_info ctinfo; | |
87 | struct tcf_ctinfo_params *cp; | |
88 | struct nf_conn *ct; | |
89 | int proto, wlen; | |
90 | int action; | |
91 | ||
92 | cp = rcu_dereference_bh(ca->params); | |
93 | ||
94 | tcf_lastuse_update(&ca->tcf_tm); | |
95 | bstats_update(&ca->tcf_bstats, skb); | |
96 | action = READ_ONCE(ca->tcf_action); | |
97 | ||
98 | wlen = skb_network_offset(skb); | |
d7bf2ebe THJ |
99 | switch (skb_protocol(skb, true)) { |
100 | case htons(ETH_P_IP): | |
24ec483c KDB |
101 | wlen += sizeof(struct iphdr); |
102 | if (!pskb_may_pull(skb, wlen)) | |
103 | goto out; | |
104 | ||
105 | proto = NFPROTO_IPV4; | |
d7bf2ebe THJ |
106 | break; |
107 | case htons(ETH_P_IPV6): | |
24ec483c KDB |
108 | wlen += sizeof(struct ipv6hdr); |
109 | if (!pskb_may_pull(skb, wlen)) | |
110 | goto out; | |
111 | ||
112 | proto = NFPROTO_IPV6; | |
d7bf2ebe THJ |
113 | break; |
114 | default: | |
24ec483c KDB |
115 | goto out; |
116 | } | |
117 | ||
118 | ct = nf_ct_get(skb, &ctinfo); | |
119 | if (!ct) { /* look harder, usually ingress */ | |
120 | if (!nf_ct_get_tuplepr(skb, skb_network_offset(skb), | |
121 | proto, cp->net, &tuple)) | |
122 | goto out; | |
123 | zone.id = cp->zone; | |
124 | zone.dir = NF_CT_DEFAULT_ZONE_DIR; | |
125 | ||
126 | thash = nf_conntrack_find_get(cp->net, &zone, &tuple); | |
127 | if (!thash) | |
128 | goto out; | |
129 | ||
130 | ct = nf_ct_tuplehash_to_ctrack(thash); | |
131 | } | |
132 | ||
133 | if (cp->mode & CTINFO_MODE_DSCP) | |
134 | if (!cp->dscpstatemask || (ct->mark & cp->dscpstatemask)) | |
135 | tcf_ctinfo_dscp_set(ct, ca, cp, skb, wlen, proto); | |
136 | ||
137 | if (cp->mode & CTINFO_MODE_CPMARK) | |
138 | tcf_ctinfo_cpmark_set(ct, ca, cp, skb); | |
139 | ||
140 | if (thash) | |
141 | nf_ct_put(ct); | |
142 | out: | |
143 | return action; | |
144 | } | |
145 | ||
146 | static const struct nla_policy ctinfo_policy[TCA_CTINFO_MAX + 1] = { | |
8140860c JB |
147 | [TCA_CTINFO_ACT] = |
148 | NLA_POLICY_EXACT_LEN(sizeof(struct tc_ctinfo)), | |
24ec483c KDB |
149 | [TCA_CTINFO_ZONE] = { .type = NLA_U16 }, |
150 | [TCA_CTINFO_PARMS_DSCP_MASK] = { .type = NLA_U32 }, | |
151 | [TCA_CTINFO_PARMS_DSCP_STATEMASK] = { .type = NLA_U32 }, | |
152 | [TCA_CTINFO_PARMS_CPMARK_MASK] = { .type = NLA_U32 }, | |
153 | }; | |
154 | ||
155 | static int tcf_ctinfo_init(struct net *net, struct nlattr *nla, | |
156 | struct nlattr *est, struct tc_action **a, | |
abbb0d33 | 157 | struct tcf_proto *tp, u32 flags, |
24ec483c KDB |
158 | struct netlink_ext_ack *extack) |
159 | { | |
160 | struct tc_action_net *tn = net_generic(net, ctinfo_net_id); | |
695176bf | 161 | bool bind = flags & TCA_ACT_FLAGS_BIND; |
7be8ef2c | 162 | u32 dscpmask = 0, dscpstatemask, index; |
24ec483c KDB |
163 | struct nlattr *tb[TCA_CTINFO_MAX + 1]; |
164 | struct tcf_ctinfo_params *cp_new; | |
165 | struct tcf_chain *goto_ch = NULL; | |
24ec483c KDB |
166 | struct tc_ctinfo *actparm; |
167 | struct tcf_ctinfo *ci; | |
168 | u8 dscpmaskshift; | |
169 | int ret = 0, err; | |
170 | ||
733f0766 KDB |
171 | if (!nla) { |
172 | NL_SET_ERR_MSG_MOD(extack, "ctinfo requires attributes to be passed"); | |
24ec483c | 173 | return -EINVAL; |
733f0766 | 174 | } |
24ec483c | 175 | |
733f0766 | 176 | err = nla_parse_nested(tb, TCA_CTINFO_MAX, nla, ctinfo_policy, extack); |
24ec483c KDB |
177 | if (err < 0) |
178 | return err; | |
179 | ||
733f0766 KDB |
180 | if (!tb[TCA_CTINFO_ACT]) { |
181 | NL_SET_ERR_MSG_MOD(extack, | |
182 | "Missing required TCA_CTINFO_ACT attribute"); | |
24ec483c | 183 | return -EINVAL; |
733f0766 | 184 | } |
24ec483c KDB |
185 | actparm = nla_data(tb[TCA_CTINFO_ACT]); |
186 | ||
187 | /* do some basic validation here before dynamically allocating things */ | |
188 | /* that we would otherwise have to clean up. */ | |
189 | if (tb[TCA_CTINFO_PARMS_DSCP_MASK]) { | |
190 | dscpmask = nla_get_u32(tb[TCA_CTINFO_PARMS_DSCP_MASK]); | |
191 | /* need contiguous 6 bit mask */ | |
192 | dscpmaskshift = dscpmask ? __ffs(dscpmask) : 0; | |
733f0766 KDB |
193 | if ((~0 & (dscpmask >> dscpmaskshift)) != 0x3f) { |
194 | NL_SET_ERR_MSG_ATTR(extack, | |
195 | tb[TCA_CTINFO_PARMS_DSCP_MASK], | |
196 | "dscp mask must be 6 contiguous bits"); | |
24ec483c | 197 | return -EINVAL; |
733f0766 | 198 | } |
24ec483c KDB |
199 | dscpstatemask = tb[TCA_CTINFO_PARMS_DSCP_STATEMASK] ? |
200 | nla_get_u32(tb[TCA_CTINFO_PARMS_DSCP_STATEMASK]) : 0; | |
201 | /* mask & statemask must not overlap */ | |
733f0766 KDB |
202 | if (dscpmask & dscpstatemask) { |
203 | NL_SET_ERR_MSG_ATTR(extack, | |
204 | tb[TCA_CTINFO_PARMS_DSCP_STATEMASK], | |
205 | "dscp statemask must not overlap dscp mask"); | |
24ec483c | 206 | return -EINVAL; |
733f0766 | 207 | } |
24ec483c KDB |
208 | } |
209 | ||
210 | /* done the validation:now to the actual action allocation */ | |
7be8ef2c DL |
211 | index = actparm->index; |
212 | err = tcf_idr_check_alloc(tn, &index, a, bind); | |
24ec483c | 213 | if (!err) { |
7be8ef2c | 214 | ret = tcf_idr_create(tn, index, est, a, |
40bd094d | 215 | &act_ctinfo_ops, bind, false, flags); |
24ec483c | 216 | if (ret) { |
7be8ef2c | 217 | tcf_idr_cleanup(tn, index); |
24ec483c KDB |
218 | return ret; |
219 | } | |
a658c2e4 | 220 | ret = ACT_P_CREATED; |
24ec483c KDB |
221 | } else if (err > 0) { |
222 | if (bind) /* don't override defaults */ | |
223 | return 0; | |
695176bf | 224 | if (!(flags & TCA_ACT_FLAGS_REPLACE)) { |
24ec483c KDB |
225 | tcf_idr_release(*a, bind); |
226 | return -EEXIST; | |
227 | } | |
228 | } else { | |
229 | return err; | |
230 | } | |
231 | ||
232 | err = tcf_action_check_ctrlact(actparm->action, tp, &goto_ch, extack); | |
233 | if (err < 0) | |
234 | goto release_idr; | |
235 | ||
236 | ci = to_ctinfo(*a); | |
237 | ||
238 | cp_new = kzalloc(sizeof(*cp_new), GFP_KERNEL); | |
239 | if (unlikely(!cp_new)) { | |
240 | err = -ENOMEM; | |
241 | goto put_chain; | |
242 | } | |
243 | ||
244 | cp_new->net = net; | |
245 | cp_new->zone = tb[TCA_CTINFO_ZONE] ? | |
246 | nla_get_u16(tb[TCA_CTINFO_ZONE]) : 0; | |
247 | if (dscpmask) { | |
248 | cp_new->dscpmask = dscpmask; | |
249 | cp_new->dscpmaskshift = dscpmaskshift; | |
250 | cp_new->dscpstatemask = dscpstatemask; | |
251 | cp_new->mode |= CTINFO_MODE_DSCP; | |
24ec483c KDB |
252 | } |
253 | ||
254 | if (tb[TCA_CTINFO_PARMS_CPMARK_MASK]) { | |
255 | cp_new->cpmarkmask = | |
256 | nla_get_u32(tb[TCA_CTINFO_PARMS_CPMARK_MASK]); | |
257 | cp_new->mode |= CTINFO_MODE_CPMARK; | |
24ec483c KDB |
258 | } |
259 | ||
260 | spin_lock_bh(&ci->tcf_lock); | |
261 | goto_ch = tcf_action_set_ctrlact(*a, actparm->action, goto_ch); | |
445d3749 PM |
262 | cp_new = rcu_replace_pointer(ci->params, cp_new, |
263 | lockdep_is_held(&ci->tcf_lock)); | |
24ec483c KDB |
264 | spin_unlock_bh(&ci->tcf_lock); |
265 | ||
266 | if (goto_ch) | |
267 | tcf_chain_put_by_act(goto_ch); | |
268 | if (cp_new) | |
269 | kfree_rcu(cp_new, rcu); | |
270 | ||
24ec483c KDB |
271 | return ret; |
272 | ||
273 | put_chain: | |
274 | if (goto_ch) | |
275 | tcf_chain_put_by_act(goto_ch); | |
276 | release_idr: | |
277 | tcf_idr_release(*a, bind); | |
278 | return err; | |
279 | } | |
280 | ||
281 | static int tcf_ctinfo_dump(struct sk_buff *skb, struct tc_action *a, | |
282 | int bind, int ref) | |
283 | { | |
284 | struct tcf_ctinfo *ci = to_ctinfo(a); | |
285 | struct tc_ctinfo opt = { | |
286 | .index = ci->tcf_index, | |
287 | .refcnt = refcount_read(&ci->tcf_refcnt) - ref, | |
288 | .bindcnt = atomic_read(&ci->tcf_bindcnt) - bind, | |
289 | }; | |
290 | unsigned char *b = skb_tail_pointer(skb); | |
291 | struct tcf_ctinfo_params *cp; | |
292 | struct tcf_t t; | |
293 | ||
294 | spin_lock_bh(&ci->tcf_lock); | |
295 | cp = rcu_dereference_protected(ci->params, | |
296 | lockdep_is_held(&ci->tcf_lock)); | |
297 | ||
298 | tcf_tm_dump(&t, &ci->tcf_tm); | |
299 | if (nla_put_64bit(skb, TCA_CTINFO_TM, sizeof(t), &t, TCA_CTINFO_PAD)) | |
300 | goto nla_put_failure; | |
301 | ||
302 | opt.action = ci->tcf_action; | |
303 | if (nla_put(skb, TCA_CTINFO_ACT, sizeof(opt), &opt)) | |
304 | goto nla_put_failure; | |
305 | ||
306 | if (nla_put_u16(skb, TCA_CTINFO_ZONE, cp->zone)) | |
307 | goto nla_put_failure; | |
308 | ||
309 | if (cp->mode & CTINFO_MODE_DSCP) { | |
310 | if (nla_put_u32(skb, TCA_CTINFO_PARMS_DSCP_MASK, | |
311 | cp->dscpmask)) | |
312 | goto nla_put_failure; | |
313 | if (nla_put_u32(skb, TCA_CTINFO_PARMS_DSCP_STATEMASK, | |
314 | cp->dscpstatemask)) | |
315 | goto nla_put_failure; | |
316 | } | |
317 | ||
318 | if (cp->mode & CTINFO_MODE_CPMARK) { | |
319 | if (nla_put_u32(skb, TCA_CTINFO_PARMS_CPMARK_MASK, | |
320 | cp->cpmarkmask)) | |
321 | goto nla_put_failure; | |
322 | } | |
323 | ||
324 | if (nla_put_u64_64bit(skb, TCA_CTINFO_STATS_DSCP_SET, | |
325 | ci->stats_dscp_set, TCA_CTINFO_PAD)) | |
326 | goto nla_put_failure; | |
327 | ||
328 | if (nla_put_u64_64bit(skb, TCA_CTINFO_STATS_DSCP_ERROR, | |
329 | ci->stats_dscp_error, TCA_CTINFO_PAD)) | |
330 | goto nla_put_failure; | |
331 | ||
332 | if (nla_put_u64_64bit(skb, TCA_CTINFO_STATS_CPMARK_SET, | |
333 | ci->stats_cpmark_set, TCA_CTINFO_PAD)) | |
334 | goto nla_put_failure; | |
335 | ||
336 | spin_unlock_bh(&ci->tcf_lock); | |
337 | return skb->len; | |
338 | ||
339 | nla_put_failure: | |
340 | spin_unlock_bh(&ci->tcf_lock); | |
341 | nlmsg_trim(skb, b); | |
342 | return -1; | |
343 | } | |
344 | ||
345 | static int tcf_ctinfo_walker(struct net *net, struct sk_buff *skb, | |
346 | struct netlink_callback *cb, int type, | |
347 | const struct tc_action_ops *ops, | |
348 | struct netlink_ext_ack *extack) | |
349 | { | |
350 | struct tc_action_net *tn = net_generic(net, ctinfo_net_id); | |
351 | ||
352 | return tcf_generic_walker(tn, skb, cb, type, ops, extack); | |
353 | } | |
354 | ||
355 | static int tcf_ctinfo_search(struct net *net, struct tc_action **a, u32 index) | |
356 | { | |
357 | struct tc_action_net *tn = net_generic(net, ctinfo_net_id); | |
358 | ||
359 | return tcf_idr_search(tn, a, index); | |
360 | } | |
361 | ||
09d4f10a ED |
362 | static void tcf_ctinfo_cleanup(struct tc_action *a) |
363 | { | |
364 | struct tcf_ctinfo *ci = to_ctinfo(a); | |
365 | struct tcf_ctinfo_params *cp; | |
366 | ||
367 | cp = rcu_dereference_protected(ci->params, 1); | |
368 | if (cp) | |
369 | kfree_rcu(cp, rcu); | |
370 | } | |
371 | ||
24ec483c KDB |
372 | static struct tc_action_ops act_ctinfo_ops = { |
373 | .kind = "ctinfo", | |
374 | .id = TCA_ID_CTINFO, | |
375 | .owner = THIS_MODULE, | |
376 | .act = tcf_ctinfo_act, | |
377 | .dump = tcf_ctinfo_dump, | |
378 | .init = tcf_ctinfo_init, | |
09d4f10a | 379 | .cleanup= tcf_ctinfo_cleanup, |
24ec483c KDB |
380 | .walk = tcf_ctinfo_walker, |
381 | .lookup = tcf_ctinfo_search, | |
382 | .size = sizeof(struct tcf_ctinfo), | |
383 | }; | |
384 | ||
385 | static __net_init int ctinfo_init_net(struct net *net) | |
386 | { | |
387 | struct tc_action_net *tn = net_generic(net, ctinfo_net_id); | |
388 | ||
981471bd | 389 | return tc_action_net_init(net, tn, &act_ctinfo_ops); |
24ec483c KDB |
390 | } |
391 | ||
392 | static void __net_exit ctinfo_exit_net(struct list_head *net_list) | |
393 | { | |
394 | tc_action_net_exit(net_list, ctinfo_net_id); | |
395 | } | |
396 | ||
397 | static struct pernet_operations ctinfo_net_ops = { | |
398 | .init = ctinfo_init_net, | |
399 | .exit_batch = ctinfo_exit_net, | |
400 | .id = &ctinfo_net_id, | |
401 | .size = sizeof(struct tc_action_net), | |
402 | }; | |
403 | ||
404 | static int __init ctinfo_init_module(void) | |
405 | { | |
406 | return tcf_register_action(&act_ctinfo_ops, &ctinfo_net_ops); | |
407 | } | |
408 | ||
409 | static void __exit ctinfo_cleanup_module(void) | |
410 | { | |
411 | tcf_unregister_action(&act_ctinfo_ops, &ctinfo_net_ops); | |
412 | } | |
413 | ||
414 | module_init(ctinfo_init_module); | |
415 | module_exit(ctinfo_cleanup_module); | |
416 | MODULE_AUTHOR("Kevin Darbyshire-Bryant <ldir@darbyshire-bryant.me.uk>"); | |
417 | MODULE_DESCRIPTION("Connection tracking mark actions"); | |
418 | MODULE_LICENSE("GPL"); |