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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); | |
99 | if (tc_skb_protocol(skb) == htons(ETH_P_IP)) { | |
100 | wlen += sizeof(struct iphdr); | |
101 | if (!pskb_may_pull(skb, wlen)) | |
102 | goto out; | |
103 | ||
104 | proto = NFPROTO_IPV4; | |
105 | } else if (tc_skb_protocol(skb) == htons(ETH_P_IPV6)) { | |
106 | wlen += sizeof(struct ipv6hdr); | |
107 | if (!pskb_may_pull(skb, wlen)) | |
108 | goto out; | |
109 | ||
110 | proto = NFPROTO_IPV6; | |
111 | } else { | |
112 | goto out; | |
113 | } | |
114 | ||
115 | ct = nf_ct_get(skb, &ctinfo); | |
116 | if (!ct) { /* look harder, usually ingress */ | |
117 | if (!nf_ct_get_tuplepr(skb, skb_network_offset(skb), | |
118 | proto, cp->net, &tuple)) | |
119 | goto out; | |
120 | zone.id = cp->zone; | |
121 | zone.dir = NF_CT_DEFAULT_ZONE_DIR; | |
122 | ||
123 | thash = nf_conntrack_find_get(cp->net, &zone, &tuple); | |
124 | if (!thash) | |
125 | goto out; | |
126 | ||
127 | ct = nf_ct_tuplehash_to_ctrack(thash); | |
128 | } | |
129 | ||
130 | if (cp->mode & CTINFO_MODE_DSCP) | |
131 | if (!cp->dscpstatemask || (ct->mark & cp->dscpstatemask)) | |
132 | tcf_ctinfo_dscp_set(ct, ca, cp, skb, wlen, proto); | |
133 | ||
134 | if (cp->mode & CTINFO_MODE_CPMARK) | |
135 | tcf_ctinfo_cpmark_set(ct, ca, cp, skb); | |
136 | ||
137 | if (thash) | |
138 | nf_ct_put(ct); | |
139 | out: | |
140 | return action; | |
141 | } | |
142 | ||
143 | static const struct nla_policy ctinfo_policy[TCA_CTINFO_MAX + 1] = { | |
c197d636 KDB |
144 | [TCA_CTINFO_ACT] = { .type = NLA_EXACT_LEN, |
145 | .len = sizeof(struct | |
24ec483c KDB |
146 | tc_ctinfo) }, |
147 | [TCA_CTINFO_ZONE] = { .type = NLA_U16 }, | |
148 | [TCA_CTINFO_PARMS_DSCP_MASK] = { .type = NLA_U32 }, | |
149 | [TCA_CTINFO_PARMS_DSCP_STATEMASK] = { .type = NLA_U32 }, | |
150 | [TCA_CTINFO_PARMS_CPMARK_MASK] = { .type = NLA_U32 }, | |
151 | }; | |
152 | ||
153 | static int tcf_ctinfo_init(struct net *net, struct nlattr *nla, | |
154 | struct nlattr *est, struct tc_action **a, | |
155 | int ovr, int bind, bool rtnl_held, | |
156 | struct tcf_proto *tp, | |
157 | struct netlink_ext_ack *extack) | |
158 | { | |
159 | struct tc_action_net *tn = net_generic(net, ctinfo_net_id); | |
160 | struct nlattr *tb[TCA_CTINFO_MAX + 1]; | |
161 | struct tcf_ctinfo_params *cp_new; | |
162 | struct tcf_chain *goto_ch = NULL; | |
163 | u32 dscpmask = 0, dscpstatemask; | |
164 | struct tc_ctinfo *actparm; | |
165 | struct tcf_ctinfo *ci; | |
166 | u8 dscpmaskshift; | |
167 | int ret = 0, err; | |
168 | ||
733f0766 KDB |
169 | if (!nla) { |
170 | NL_SET_ERR_MSG_MOD(extack, "ctinfo requires attributes to be passed"); | |
24ec483c | 171 | return -EINVAL; |
733f0766 | 172 | } |
24ec483c | 173 | |
733f0766 | 174 | err = nla_parse_nested(tb, TCA_CTINFO_MAX, nla, ctinfo_policy, extack); |
24ec483c KDB |
175 | if (err < 0) |
176 | return err; | |
177 | ||
733f0766 KDB |
178 | if (!tb[TCA_CTINFO_ACT]) { |
179 | NL_SET_ERR_MSG_MOD(extack, | |
180 | "Missing required TCA_CTINFO_ACT attribute"); | |
24ec483c | 181 | return -EINVAL; |
733f0766 | 182 | } |
24ec483c KDB |
183 | actparm = nla_data(tb[TCA_CTINFO_ACT]); |
184 | ||
185 | /* do some basic validation here before dynamically allocating things */ | |
186 | /* that we would otherwise have to clean up. */ | |
187 | if (tb[TCA_CTINFO_PARMS_DSCP_MASK]) { | |
188 | dscpmask = nla_get_u32(tb[TCA_CTINFO_PARMS_DSCP_MASK]); | |
189 | /* need contiguous 6 bit mask */ | |
190 | dscpmaskshift = dscpmask ? __ffs(dscpmask) : 0; | |
733f0766 KDB |
191 | if ((~0 & (dscpmask >> dscpmaskshift)) != 0x3f) { |
192 | NL_SET_ERR_MSG_ATTR(extack, | |
193 | tb[TCA_CTINFO_PARMS_DSCP_MASK], | |
194 | "dscp mask must be 6 contiguous bits"); | |
24ec483c | 195 | return -EINVAL; |
733f0766 | 196 | } |
24ec483c KDB |
197 | dscpstatemask = tb[TCA_CTINFO_PARMS_DSCP_STATEMASK] ? |
198 | nla_get_u32(tb[TCA_CTINFO_PARMS_DSCP_STATEMASK]) : 0; | |
199 | /* mask & statemask must not overlap */ | |
733f0766 KDB |
200 | if (dscpmask & dscpstatemask) { |
201 | NL_SET_ERR_MSG_ATTR(extack, | |
202 | tb[TCA_CTINFO_PARMS_DSCP_STATEMASK], | |
203 | "dscp statemask must not overlap dscp mask"); | |
24ec483c | 204 | return -EINVAL; |
733f0766 | 205 | } |
24ec483c KDB |
206 | } |
207 | ||
208 | /* done the validation:now to the actual action allocation */ | |
209 | err = tcf_idr_check_alloc(tn, &actparm->index, a, bind); | |
210 | if (!err) { | |
211 | ret = tcf_idr_create(tn, actparm->index, est, a, | |
212 | &act_ctinfo_ops, bind, false); | |
213 | if (ret) { | |
214 | tcf_idr_cleanup(tn, actparm->index); | |
215 | return ret; | |
216 | } | |
a658c2e4 | 217 | ret = ACT_P_CREATED; |
24ec483c KDB |
218 | } else if (err > 0) { |
219 | if (bind) /* don't override defaults */ | |
220 | return 0; | |
221 | if (!ovr) { | |
222 | tcf_idr_release(*a, bind); | |
223 | return -EEXIST; | |
224 | } | |
225 | } else { | |
226 | return err; | |
227 | } | |
228 | ||
229 | err = tcf_action_check_ctrlact(actparm->action, tp, &goto_ch, extack); | |
230 | if (err < 0) | |
231 | goto release_idr; | |
232 | ||
233 | ci = to_ctinfo(*a); | |
234 | ||
235 | cp_new = kzalloc(sizeof(*cp_new), GFP_KERNEL); | |
236 | if (unlikely(!cp_new)) { | |
237 | err = -ENOMEM; | |
238 | goto put_chain; | |
239 | } | |
240 | ||
241 | cp_new->net = net; | |
242 | cp_new->zone = tb[TCA_CTINFO_ZONE] ? | |
243 | nla_get_u16(tb[TCA_CTINFO_ZONE]) : 0; | |
244 | if (dscpmask) { | |
245 | cp_new->dscpmask = dscpmask; | |
246 | cp_new->dscpmaskshift = dscpmaskshift; | |
247 | cp_new->dscpstatemask = dscpstatemask; | |
248 | cp_new->mode |= CTINFO_MODE_DSCP; | |
24ec483c KDB |
249 | } |
250 | ||
251 | if (tb[TCA_CTINFO_PARMS_CPMARK_MASK]) { | |
252 | cp_new->cpmarkmask = | |
253 | nla_get_u32(tb[TCA_CTINFO_PARMS_CPMARK_MASK]); | |
254 | cp_new->mode |= CTINFO_MODE_CPMARK; | |
24ec483c KDB |
255 | } |
256 | ||
257 | spin_lock_bh(&ci->tcf_lock); | |
258 | goto_ch = tcf_action_set_ctrlact(*a, actparm->action, goto_ch); | |
259 | rcu_swap_protected(ci->params, cp_new, | |
260 | lockdep_is_held(&ci->tcf_lock)); | |
261 | spin_unlock_bh(&ci->tcf_lock); | |
262 | ||
263 | if (goto_ch) | |
264 | tcf_chain_put_by_act(goto_ch); | |
265 | if (cp_new) | |
266 | kfree_rcu(cp_new, rcu); | |
267 | ||
268 | if (ret == ACT_P_CREATED) | |
269 | tcf_idr_insert(tn, *a); | |
270 | ||
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 | ||
362 | static struct tc_action_ops act_ctinfo_ops = { | |
363 | .kind = "ctinfo", | |
364 | .id = TCA_ID_CTINFO, | |
365 | .owner = THIS_MODULE, | |
366 | .act = tcf_ctinfo_act, | |
367 | .dump = tcf_ctinfo_dump, | |
368 | .init = tcf_ctinfo_init, | |
369 | .walk = tcf_ctinfo_walker, | |
370 | .lookup = tcf_ctinfo_search, | |
371 | .size = sizeof(struct tcf_ctinfo), | |
372 | }; | |
373 | ||
374 | static __net_init int ctinfo_init_net(struct net *net) | |
375 | { | |
376 | struct tc_action_net *tn = net_generic(net, ctinfo_net_id); | |
377 | ||
378 | return tc_action_net_init(tn, &act_ctinfo_ops); | |
379 | } | |
380 | ||
381 | static void __net_exit ctinfo_exit_net(struct list_head *net_list) | |
382 | { | |
383 | tc_action_net_exit(net_list, ctinfo_net_id); | |
384 | } | |
385 | ||
386 | static struct pernet_operations ctinfo_net_ops = { | |
387 | .init = ctinfo_init_net, | |
388 | .exit_batch = ctinfo_exit_net, | |
389 | .id = &ctinfo_net_id, | |
390 | .size = sizeof(struct tc_action_net), | |
391 | }; | |
392 | ||
393 | static int __init ctinfo_init_module(void) | |
394 | { | |
395 | return tcf_register_action(&act_ctinfo_ops, &ctinfo_net_ops); | |
396 | } | |
397 | ||
398 | static void __exit ctinfo_cleanup_module(void) | |
399 | { | |
400 | tcf_unregister_action(&act_ctinfo_ops, &ctinfo_net_ops); | |
401 | } | |
402 | ||
403 | module_init(ctinfo_init_module); | |
404 | module_exit(ctinfo_cleanup_module); | |
405 | MODULE_AUTHOR("Kevin Darbyshire-Bryant <ldir@darbyshire-bryant.me.uk>"); | |
406 | MODULE_DESCRIPTION("Connection tracking mark actions"); | |
407 | MODULE_LICENSE("GPL"); |