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
tcf_ctinfo_dscp_set(struct nf_conn * ct,struct tcf_ctinfo * ca,struct tcf_ctinfo_params * cp,struct sk_buff * skb,int wlen,int proto)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
tcf_ctinfo_cpmark_set(struct nf_conn * ct,struct tcf_ctinfo * ca,struct tcf_ctinfo_params * cp,struct sk_buff * skb)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
tcf_ctinfo_act(struct sk_buff * skb,const struct tc_action * a,struct tcf_result * res)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] = {
144 [TCA_CTINFO_ACT] = { .type = NLA_EXACT_LEN,
145 .len = sizeof(struct
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
tcf_ctinfo_init(struct net * net,struct nlattr * nla,struct nlattr * est,struct tc_action ** a,int ovr,int bind,bool rtnl_held,struct tcf_proto * tp,struct netlink_ext_ack * extack)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 u32 dscpmask = 0, dscpstatemask, index;
161 struct nlattr *tb[TCA_CTINFO_MAX + 1];
162 struct tcf_ctinfo_params *cp_new;
163 struct tcf_chain *goto_ch = NULL;
164 struct tc_ctinfo *actparm;
165 struct tcf_ctinfo *ci;
166 u8 dscpmaskshift;
167 int ret = 0, err;
168
169 if (!nla) {
170 NL_SET_ERR_MSG_MOD(extack, "ctinfo requires attributes to be passed");
171 return -EINVAL;
172 }
173
174 err = nla_parse_nested(tb, TCA_CTINFO_MAX, nla, ctinfo_policy, extack);
175 if (err < 0)
176 return err;
177
178 if (!tb[TCA_CTINFO_ACT]) {
179 NL_SET_ERR_MSG_MOD(extack,
180 "Missing required TCA_CTINFO_ACT attribute");
181 return -EINVAL;
182 }
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;
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");
195 return -EINVAL;
196 }
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 */
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");
204 return -EINVAL;
205 }
206 }
207
208 /* done the validation:now to the actual action allocation */
209 index = actparm->index;
210 err = tcf_idr_check_alloc(tn, &index, a, bind);
211 if (!err) {
212 ret = tcf_idr_create(tn, index, est, a,
213 &act_ctinfo_ops, bind, false);
214 if (ret) {
215 tcf_idr_cleanup(tn, index);
216 return ret;
217 }
218 ret = ACT_P_CREATED;
219 } else if (err > 0) {
220 if (bind) /* don't override defaults */
221 return 0;
222 if (!ovr) {
223 tcf_idr_release(*a, bind);
224 return -EEXIST;
225 }
226 } else {
227 return err;
228 }
229
230 err = tcf_action_check_ctrlact(actparm->action, tp, &goto_ch, extack);
231 if (err < 0)
232 goto release_idr;
233
234 ci = to_ctinfo(*a);
235
236 cp_new = kzalloc(sizeof(*cp_new), GFP_KERNEL);
237 if (unlikely(!cp_new)) {
238 err = -ENOMEM;
239 goto put_chain;
240 }
241
242 cp_new->net = net;
243 cp_new->zone = tb[TCA_CTINFO_ZONE] ?
244 nla_get_u16(tb[TCA_CTINFO_ZONE]) : 0;
245 if (dscpmask) {
246 cp_new->dscpmask = dscpmask;
247 cp_new->dscpmaskshift = dscpmaskshift;
248 cp_new->dscpstatemask = dscpstatemask;
249 cp_new->mode |= CTINFO_MODE_DSCP;
250 }
251
252 if (tb[TCA_CTINFO_PARMS_CPMARK_MASK]) {
253 cp_new->cpmarkmask =
254 nla_get_u32(tb[TCA_CTINFO_PARMS_CPMARK_MASK]);
255 cp_new->mode |= CTINFO_MODE_CPMARK;
256 }
257
258 spin_lock_bh(&ci->tcf_lock);
259 goto_ch = tcf_action_set_ctrlact(*a, actparm->action, goto_ch);
260 rcu_swap_protected(ci->params, cp_new,
261 lockdep_is_held(&ci->tcf_lock));
262 spin_unlock_bh(&ci->tcf_lock);
263
264 if (goto_ch)
265 tcf_chain_put_by_act(goto_ch);
266 if (cp_new)
267 kfree_rcu(cp_new, rcu);
268
269 if (ret == ACT_P_CREATED)
270 tcf_idr_insert(tn, *a);
271
272 return ret;
273
274 put_chain:
275 if (goto_ch)
276 tcf_chain_put_by_act(goto_ch);
277 release_idr:
278 tcf_idr_release(*a, bind);
279 return err;
280 }
281
tcf_ctinfo_dump(struct sk_buff * skb,struct tc_action * a,int bind,int ref)282 static int tcf_ctinfo_dump(struct sk_buff *skb, struct tc_action *a,
283 int bind, int ref)
284 {
285 struct tcf_ctinfo *ci = to_ctinfo(a);
286 struct tc_ctinfo opt = {
287 .index = ci->tcf_index,
288 .refcnt = refcount_read(&ci->tcf_refcnt) - ref,
289 .bindcnt = atomic_read(&ci->tcf_bindcnt) - bind,
290 };
291 unsigned char *b = skb_tail_pointer(skb);
292 struct tcf_ctinfo_params *cp;
293 struct tcf_t t;
294
295 spin_lock_bh(&ci->tcf_lock);
296 cp = rcu_dereference_protected(ci->params,
297 lockdep_is_held(&ci->tcf_lock));
298
299 tcf_tm_dump(&t, &ci->tcf_tm);
300 if (nla_put_64bit(skb, TCA_CTINFO_TM, sizeof(t), &t, TCA_CTINFO_PAD))
301 goto nla_put_failure;
302
303 opt.action = ci->tcf_action;
304 if (nla_put(skb, TCA_CTINFO_ACT, sizeof(opt), &opt))
305 goto nla_put_failure;
306
307 if (nla_put_u16(skb, TCA_CTINFO_ZONE, cp->zone))
308 goto nla_put_failure;
309
310 if (cp->mode & CTINFO_MODE_DSCP) {
311 if (nla_put_u32(skb, TCA_CTINFO_PARMS_DSCP_MASK,
312 cp->dscpmask))
313 goto nla_put_failure;
314 if (nla_put_u32(skb, TCA_CTINFO_PARMS_DSCP_STATEMASK,
315 cp->dscpstatemask))
316 goto nla_put_failure;
317 }
318
319 if (cp->mode & CTINFO_MODE_CPMARK) {
320 if (nla_put_u32(skb, TCA_CTINFO_PARMS_CPMARK_MASK,
321 cp->cpmarkmask))
322 goto nla_put_failure;
323 }
324
325 if (nla_put_u64_64bit(skb, TCA_CTINFO_STATS_DSCP_SET,
326 ci->stats_dscp_set, TCA_CTINFO_PAD))
327 goto nla_put_failure;
328
329 if (nla_put_u64_64bit(skb, TCA_CTINFO_STATS_DSCP_ERROR,
330 ci->stats_dscp_error, TCA_CTINFO_PAD))
331 goto nla_put_failure;
332
333 if (nla_put_u64_64bit(skb, TCA_CTINFO_STATS_CPMARK_SET,
334 ci->stats_cpmark_set, TCA_CTINFO_PAD))
335 goto nla_put_failure;
336
337 spin_unlock_bh(&ci->tcf_lock);
338 return skb->len;
339
340 nla_put_failure:
341 spin_unlock_bh(&ci->tcf_lock);
342 nlmsg_trim(skb, b);
343 return -1;
344 }
345
tcf_ctinfo_walker(struct net * net,struct sk_buff * skb,struct netlink_callback * cb,int type,const struct tc_action_ops * ops,struct netlink_ext_ack * extack)346 static int tcf_ctinfo_walker(struct net *net, struct sk_buff *skb,
347 struct netlink_callback *cb, int type,
348 const struct tc_action_ops *ops,
349 struct netlink_ext_ack *extack)
350 {
351 struct tc_action_net *tn = net_generic(net, ctinfo_net_id);
352
353 return tcf_generic_walker(tn, skb, cb, type, ops, extack);
354 }
355
tcf_ctinfo_search(struct net * net,struct tc_action ** a,u32 index)356 static int tcf_ctinfo_search(struct net *net, struct tc_action **a, u32 index)
357 {
358 struct tc_action_net *tn = net_generic(net, ctinfo_net_id);
359
360 return tcf_idr_search(tn, a, index);
361 }
362
tcf_ctinfo_cleanup(struct tc_action * a)363 static void tcf_ctinfo_cleanup(struct tc_action *a)
364 {
365 struct tcf_ctinfo *ci = to_ctinfo(a);
366 struct tcf_ctinfo_params *cp;
367
368 cp = rcu_dereference_protected(ci->params, 1);
369 if (cp)
370 kfree_rcu(cp, rcu);
371 }
372
373 static struct tc_action_ops act_ctinfo_ops = {
374 .kind = "ctinfo",
375 .id = TCA_ID_CTINFO,
376 .owner = THIS_MODULE,
377 .act = tcf_ctinfo_act,
378 .dump = tcf_ctinfo_dump,
379 .init = tcf_ctinfo_init,
380 .cleanup= tcf_ctinfo_cleanup,
381 .walk = tcf_ctinfo_walker,
382 .lookup = tcf_ctinfo_search,
383 .size = sizeof(struct tcf_ctinfo),
384 };
385
ctinfo_init_net(struct net * net)386 static __net_init int ctinfo_init_net(struct net *net)
387 {
388 struct tc_action_net *tn = net_generic(net, ctinfo_net_id);
389
390 return tc_action_net_init(net, tn, &act_ctinfo_ops);
391 }
392
ctinfo_exit_net(struct list_head * net_list)393 static void __net_exit ctinfo_exit_net(struct list_head *net_list)
394 {
395 tc_action_net_exit(net_list, ctinfo_net_id);
396 }
397
398 static struct pernet_operations ctinfo_net_ops = {
399 .init = ctinfo_init_net,
400 .exit_batch = ctinfo_exit_net,
401 .id = &ctinfo_net_id,
402 .size = sizeof(struct tc_action_net),
403 };
404
ctinfo_init_module(void)405 static int __init ctinfo_init_module(void)
406 {
407 return tcf_register_action(&act_ctinfo_ops, &ctinfo_net_ops);
408 }
409
ctinfo_cleanup_module(void)410 static void __exit ctinfo_cleanup_module(void)
411 {
412 tcf_unregister_action(&act_ctinfo_ops, &ctinfo_net_ops);
413 }
414
415 module_init(ctinfo_init_module);
416 module_exit(ctinfo_cleanup_module);
417 MODULE_AUTHOR("Kevin Darbyshire-Bryant <ldir@darbyshire-bryant.me.uk>");
418 MODULE_DESCRIPTION("Connection tracking mark actions");
419 MODULE_LICENSE("GPL");
420