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 | #include <net/tc_wrapper.h> |
22 | |
23 | #include <net/netfilter/nf_conntrack.h> |
24 | #include <net/netfilter/nf_conntrack_core.h> |
25 | #include <net/netfilter/nf_conntrack_ecache.h> |
26 | #include <net/netfilter/nf_conntrack_zones.h> |
27 | |
28 | static struct tc_action_ops act_ctinfo_ops; |
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 = (((READ_ONCE(ct->mark) & cp->dscpmask) >> cp->dscpmaskshift) << 2) & |
37 | ~INET_ECN_MASK; |
38 | |
39 | switch (proto) { |
40 | case NFPROTO_IPV4: |
41 | dscp = ipv4_get_dsfield(iph: ip_hdr(skb)) & ~INET_ECN_MASK; |
42 | if (dscp != newdscp) { |
43 | if (likely(!skb_try_make_writable(skb, wlen))) { |
44 | ipv4_change_dsfield(iph: ip_hdr(skb), |
45 | mask: INET_ECN_MASK, |
46 | value: 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(ipv6h: ipv6_hdr(skb)) & ~INET_ECN_MASK; |
55 | if (dscp != newdscp) { |
56 | if (likely(!skb_try_make_writable(skb, wlen))) { |
57 | ipv6_change_dsfield(ipv6h: ipv6_hdr(skb), |
58 | mask: INET_ECN_MASK, |
59 | value: 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 = READ_ONCE(ct->mark) & cp->cpmarkmask; |
77 | } |
78 | |
79 | TC_INDIRECT_SCOPE int tcf_ctinfo_act(struct sk_buff *skb, |
80 | const struct tc_action *a, |
81 | struct tcf_result *res) |
82 | { |
83 | const struct nf_conntrack_tuple_hash *thash = NULL; |
84 | struct tcf_ctinfo *ca = to_ctinfo(a); |
85 | struct nf_conntrack_tuple tuple; |
86 | struct nf_conntrack_zone zone; |
87 | enum ip_conntrack_info ctinfo; |
88 | struct tcf_ctinfo_params *cp; |
89 | struct nf_conn *ct; |
90 | int proto, wlen; |
91 | int action; |
92 | |
93 | cp = rcu_dereference_bh(ca->params); |
94 | |
95 | tcf_lastuse_update(tm: &ca->tcf_tm); |
96 | tcf_action_update_bstats(a: &ca->common, skb); |
97 | action = READ_ONCE(ca->tcf_action); |
98 | |
99 | wlen = skb_network_offset(skb); |
100 | switch (skb_protocol(skb, skip_vlan: true)) { |
101 | case htons(ETH_P_IP): |
102 | wlen += sizeof(struct iphdr); |
103 | if (!pskb_may_pull(skb, len: wlen)) |
104 | goto out; |
105 | |
106 | proto = NFPROTO_IPV4; |
107 | break; |
108 | case htons(ETH_P_IPV6): |
109 | wlen += sizeof(struct ipv6hdr); |
110 | if (!pskb_may_pull(skb, len: wlen)) |
111 | goto out; |
112 | |
113 | proto = NFPROTO_IPV6; |
114 | break; |
115 | default: |
116 | goto out; |
117 | } |
118 | |
119 | ct = nf_ct_get(skb, ctinfo: &ctinfo); |
120 | if (!ct) { /* look harder, usually ingress */ |
121 | if (!nf_ct_get_tuplepr(skb, nhoff: skb_network_offset(skb), |
122 | l3num: proto, net: cp->net, tuple: &tuple)) |
123 | goto out; |
124 | zone.id = cp->zone; |
125 | zone.dir = NF_CT_DEFAULT_ZONE_DIR; |
126 | |
127 | thash = nf_conntrack_find_get(net: cp->net, zone: &zone, tuple: &tuple); |
128 | if (!thash) |
129 | goto out; |
130 | |
131 | ct = nf_ct_tuplehash_to_ctrack(hash: thash); |
132 | } |
133 | |
134 | if (cp->mode & CTINFO_MODE_DSCP) |
135 | if (!cp->dscpstatemask || (READ_ONCE(ct->mark) & cp->dscpstatemask)) |
136 | tcf_ctinfo_dscp_set(ct, ca, cp, skb, wlen, proto); |
137 | |
138 | if (cp->mode & CTINFO_MODE_CPMARK) |
139 | tcf_ctinfo_cpmark_set(ct, ca, cp, skb); |
140 | |
141 | if (thash) |
142 | nf_ct_put(ct); |
143 | out: |
144 | return action; |
145 | } |
146 | |
147 | static const struct nla_policy ctinfo_policy[TCA_CTINFO_MAX + 1] = { |
148 | [TCA_CTINFO_ACT] = |
149 | NLA_POLICY_EXACT_LEN(sizeof(struct tc_ctinfo)), |
150 | [TCA_CTINFO_ZONE] = { .type = NLA_U16 }, |
151 | [TCA_CTINFO_PARMS_DSCP_MASK] = { .type = NLA_U32 }, |
152 | [TCA_CTINFO_PARMS_DSCP_STATEMASK] = { .type = NLA_U32 }, |
153 | [TCA_CTINFO_PARMS_CPMARK_MASK] = { .type = NLA_U32 }, |
154 | }; |
155 | |
156 | static int tcf_ctinfo_init(struct net *net, struct nlattr *nla, |
157 | struct nlattr *est, struct tc_action **a, |
158 | struct tcf_proto *tp, u32 flags, |
159 | struct netlink_ext_ack *extack) |
160 | { |
161 | struct tc_action_net *tn = net_generic(net, id: act_ctinfo_ops.net_id); |
162 | bool bind = flags & TCA_ACT_FLAGS_BIND; |
163 | u32 dscpmask = 0, dscpstatemask, index; |
164 | struct nlattr *tb[TCA_CTINFO_MAX + 1]; |
165 | struct tcf_ctinfo_params *cp_new; |
166 | struct tcf_chain *goto_ch = NULL; |
167 | struct tc_ctinfo *actparm; |
168 | struct tcf_ctinfo *ci; |
169 | u8 dscpmaskshift; |
170 | int ret = 0, err; |
171 | |
172 | if (!nla) { |
173 | NL_SET_ERR_MSG_MOD(extack, "ctinfo requires attributes to be passed" ); |
174 | return -EINVAL; |
175 | } |
176 | |
177 | err = nla_parse_nested(tb, TCA_CTINFO_MAX, nla, policy: ctinfo_policy, extack); |
178 | if (err < 0) |
179 | return err; |
180 | |
181 | if (!tb[TCA_CTINFO_ACT]) { |
182 | NL_SET_ERR_MSG_MOD(extack, |
183 | "Missing required TCA_CTINFO_ACT attribute" ); |
184 | return -EINVAL; |
185 | } |
186 | actparm = nla_data(nla: tb[TCA_CTINFO_ACT]); |
187 | |
188 | /* do some basic validation here before dynamically allocating things */ |
189 | /* that we would otherwise have to clean up. */ |
190 | if (tb[TCA_CTINFO_PARMS_DSCP_MASK]) { |
191 | dscpmask = nla_get_u32(nla: tb[TCA_CTINFO_PARMS_DSCP_MASK]); |
192 | /* need contiguous 6 bit mask */ |
193 | dscpmaskshift = dscpmask ? __ffs(dscpmask) : 0; |
194 | if ((~0 & (dscpmask >> dscpmaskshift)) != 0x3f) { |
195 | NL_SET_ERR_MSG_ATTR(extack, |
196 | tb[TCA_CTINFO_PARMS_DSCP_MASK], |
197 | "dscp mask must be 6 contiguous bits" ); |
198 | return -EINVAL; |
199 | } |
200 | dscpstatemask = tb[TCA_CTINFO_PARMS_DSCP_STATEMASK] ? |
201 | nla_get_u32(nla: tb[TCA_CTINFO_PARMS_DSCP_STATEMASK]) : 0; |
202 | /* mask & statemask must not overlap */ |
203 | if (dscpmask & dscpstatemask) { |
204 | NL_SET_ERR_MSG_ATTR(extack, |
205 | tb[TCA_CTINFO_PARMS_DSCP_STATEMASK], |
206 | "dscp statemask must not overlap dscp mask" ); |
207 | return -EINVAL; |
208 | } |
209 | } |
210 | |
211 | /* done the validation:now to the actual action allocation */ |
212 | index = actparm->index; |
213 | err = tcf_idr_check_alloc(tn, index: &index, a, bind); |
214 | if (!err) { |
215 | ret = tcf_idr_create_from_flags(tn, index, est, a, |
216 | ops: &act_ctinfo_ops, bind, flags); |
217 | if (ret) { |
218 | tcf_idr_cleanup(tn, index); |
219 | return ret; |
220 | } |
221 | ret = ACT_P_CREATED; |
222 | } else if (err > 0) { |
223 | if (bind) /* don't override defaults */ |
224 | return ACT_P_BOUND; |
225 | if (!(flags & TCA_ACT_FLAGS_REPLACE)) { |
226 | tcf_idr_release(a: *a, bind); |
227 | return -EEXIST; |
228 | } |
229 | } else { |
230 | return err; |
231 | } |
232 | |
233 | err = tcf_action_check_ctrlact(action: actparm->action, tp, handle: &goto_ch, newchain: extack); |
234 | if (err < 0) |
235 | goto release_idr; |
236 | |
237 | ci = to_ctinfo(*a); |
238 | |
239 | cp_new = kzalloc(size: sizeof(*cp_new), GFP_KERNEL); |
240 | if (unlikely(!cp_new)) { |
241 | err = -ENOMEM; |
242 | goto put_chain; |
243 | } |
244 | |
245 | cp_new->net = net; |
246 | cp_new->zone = tb[TCA_CTINFO_ZONE] ? |
247 | nla_get_u16(nla: tb[TCA_CTINFO_ZONE]) : 0; |
248 | if (dscpmask) { |
249 | cp_new->dscpmask = dscpmask; |
250 | cp_new->dscpmaskshift = dscpmaskshift; |
251 | cp_new->dscpstatemask = dscpstatemask; |
252 | cp_new->mode |= CTINFO_MODE_DSCP; |
253 | } |
254 | |
255 | if (tb[TCA_CTINFO_PARMS_CPMARK_MASK]) { |
256 | cp_new->cpmarkmask = |
257 | nla_get_u32(nla: tb[TCA_CTINFO_PARMS_CPMARK_MASK]); |
258 | cp_new->mode |= CTINFO_MODE_CPMARK; |
259 | } |
260 | |
261 | spin_lock_bh(lock: &ci->tcf_lock); |
262 | goto_ch = tcf_action_set_ctrlact(a: *a, action: actparm->action, newchain: goto_ch); |
263 | cp_new = rcu_replace_pointer(ci->params, cp_new, |
264 | lockdep_is_held(&ci->tcf_lock)); |
265 | spin_unlock_bh(lock: &ci->tcf_lock); |
266 | |
267 | if (goto_ch) |
268 | tcf_chain_put_by_act(chain: goto_ch); |
269 | if (cp_new) |
270 | kfree_rcu(cp_new, rcu); |
271 | |
272 | return ret; |
273 | |
274 | put_chain: |
275 | if (goto_ch) |
276 | tcf_chain_put_by_act(chain: goto_ch); |
277 | release_idr: |
278 | tcf_idr_release(a: *a, bind); |
279 | return err; |
280 | } |
281 | |
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(r: &ci->tcf_refcnt) - ref, |
289 | .bindcnt = atomic_read(v: &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(lock: &ci->tcf_lock); |
296 | cp = rcu_dereference_protected(ci->params, |
297 | lockdep_is_held(&ci->tcf_lock)); |
298 | |
299 | tcf_tm_dump(dtm: &t, stm: &ci->tcf_tm); |
300 | if (nla_put_64bit(skb, attrtype: TCA_CTINFO_TM, attrlen: sizeof(t), data: &t, padattr: TCA_CTINFO_PAD)) |
301 | goto nla_put_failure; |
302 | |
303 | opt.action = ci->tcf_action; |
304 | if (nla_put(skb, attrtype: TCA_CTINFO_ACT, attrlen: sizeof(opt), data: &opt)) |
305 | goto nla_put_failure; |
306 | |
307 | if (nla_put_u16(skb, attrtype: TCA_CTINFO_ZONE, value: cp->zone)) |
308 | goto nla_put_failure; |
309 | |
310 | if (cp->mode & CTINFO_MODE_DSCP) { |
311 | if (nla_put_u32(skb, attrtype: TCA_CTINFO_PARMS_DSCP_MASK, |
312 | value: cp->dscpmask)) |
313 | goto nla_put_failure; |
314 | if (nla_put_u32(skb, attrtype: TCA_CTINFO_PARMS_DSCP_STATEMASK, |
315 | value: cp->dscpstatemask)) |
316 | goto nla_put_failure; |
317 | } |
318 | |
319 | if (cp->mode & CTINFO_MODE_CPMARK) { |
320 | if (nla_put_u32(skb, attrtype: TCA_CTINFO_PARMS_CPMARK_MASK, |
321 | value: cp->cpmarkmask)) |
322 | goto nla_put_failure; |
323 | } |
324 | |
325 | if (nla_put_u64_64bit(skb, attrtype: TCA_CTINFO_STATS_DSCP_SET, |
326 | value: ci->stats_dscp_set, padattr: TCA_CTINFO_PAD)) |
327 | goto nla_put_failure; |
328 | |
329 | if (nla_put_u64_64bit(skb, attrtype: TCA_CTINFO_STATS_DSCP_ERROR, |
330 | value: ci->stats_dscp_error, padattr: TCA_CTINFO_PAD)) |
331 | goto nla_put_failure; |
332 | |
333 | if (nla_put_u64_64bit(skb, attrtype: TCA_CTINFO_STATS_CPMARK_SET, |
334 | value: ci->stats_cpmark_set, padattr: TCA_CTINFO_PAD)) |
335 | goto nla_put_failure; |
336 | |
337 | spin_unlock_bh(lock: &ci->tcf_lock); |
338 | return skb->len; |
339 | |
340 | nla_put_failure: |
341 | spin_unlock_bh(lock: &ci->tcf_lock); |
342 | nlmsg_trim(skb, mark: b); |
343 | return -1; |
344 | } |
345 | |
346 | static void tcf_ctinfo_cleanup(struct tc_action *a) |
347 | { |
348 | struct tcf_ctinfo *ci = to_ctinfo(a); |
349 | struct tcf_ctinfo_params *cp; |
350 | |
351 | cp = rcu_dereference_protected(ci->params, 1); |
352 | if (cp) |
353 | kfree_rcu(cp, rcu); |
354 | } |
355 | |
356 | static struct tc_action_ops act_ctinfo_ops = { |
357 | .kind = "ctinfo" , |
358 | .id = TCA_ID_CTINFO, |
359 | .owner = THIS_MODULE, |
360 | .act = tcf_ctinfo_act, |
361 | .dump = tcf_ctinfo_dump, |
362 | .init = tcf_ctinfo_init, |
363 | .cleanup= tcf_ctinfo_cleanup, |
364 | .size = sizeof(struct tcf_ctinfo), |
365 | }; |
366 | MODULE_ALIAS_NET_ACT("ctinfo" ); |
367 | |
368 | static __net_init int ctinfo_init_net(struct net *net) |
369 | { |
370 | struct tc_action_net *tn = net_generic(net, id: act_ctinfo_ops.net_id); |
371 | |
372 | return tc_action_net_init(net, tn, ops: &act_ctinfo_ops); |
373 | } |
374 | |
375 | static void __net_exit ctinfo_exit_net(struct list_head *net_list) |
376 | { |
377 | tc_action_net_exit(net_list, id: act_ctinfo_ops.net_id); |
378 | } |
379 | |
380 | static struct pernet_operations ctinfo_net_ops = { |
381 | .init = ctinfo_init_net, |
382 | .exit_batch = ctinfo_exit_net, |
383 | .id = &act_ctinfo_ops.net_id, |
384 | .size = sizeof(struct tc_action_net), |
385 | }; |
386 | |
387 | static int __init ctinfo_init_module(void) |
388 | { |
389 | return tcf_register_action(a: &act_ctinfo_ops, ops: &ctinfo_net_ops); |
390 | } |
391 | |
392 | static void __exit ctinfo_cleanup_module(void) |
393 | { |
394 | tcf_unregister_action(a: &act_ctinfo_ops, ops: &ctinfo_net_ops); |
395 | } |
396 | |
397 | module_init(ctinfo_init_module); |
398 | module_exit(ctinfo_cleanup_module); |
399 | MODULE_AUTHOR("Kevin Darbyshire-Bryant <ldir@darbyshire-bryant.me.uk>" ); |
400 | MODULE_DESCRIPTION("Connection tracking mark actions" ); |
401 | MODULE_LICENSE("GPL" ); |
402 | |