1
2
3
4
5
6
7
8
9
10
11
12#include <linux/types.h>
13#include <linux/kernel.h>
14#include <linux/string.h>
15#include <linux/errno.h>
16#include <linux/skbuff.h>
17#include <linux/rtnetlink.h>
18#include <linux/module.h>
19#include <linux/init.h>
20#include <linux/slab.h>
21#include <net/netlink.h>
22#include <net/pkt_sched.h>
23#include <linux/tc_act/tc_pedit.h>
24#include <net/tc_act/tc_pedit.h>
25#include <uapi/linux/tc_act/tc_pedit.h>
26
27static unsigned int pedit_net_id;
28static struct tc_action_ops act_pedit_ops;
29
30static const struct nla_policy pedit_policy[TCA_PEDIT_MAX + 1] = {
31 [TCA_PEDIT_PARMS] = { .len = sizeof(struct tc_pedit) },
32 [TCA_PEDIT_KEYS_EX] = { .type = NLA_NESTED },
33};
34
35static const struct nla_policy pedit_key_ex_policy[TCA_PEDIT_KEY_EX_MAX + 1] = {
36 [TCA_PEDIT_KEY_EX_HTYPE] = { .type = NLA_U16 },
37 [TCA_PEDIT_KEY_EX_CMD] = { .type = NLA_U16 },
38};
39
40static struct tcf_pedit_key_ex *tcf_pedit_keys_ex_parse(struct nlattr *nla,
41 u8 n)
42{
43 struct tcf_pedit_key_ex *keys_ex;
44 struct tcf_pedit_key_ex *k;
45 const struct nlattr *ka;
46 int err = -EINVAL;
47 int rem;
48
49 if (!nla || !n)
50 return NULL;
51
52 keys_ex = kcalloc(n, sizeof(*k), GFP_KERNEL);
53 if (!keys_ex)
54 return ERR_PTR(-ENOMEM);
55
56 k = keys_ex;
57
58 nla_for_each_nested(ka, nla, rem) {
59 struct nlattr *tb[TCA_PEDIT_KEY_EX_MAX + 1];
60
61 if (!n) {
62 err = -EINVAL;
63 goto err_out;
64 }
65 n--;
66
67 if (nla_type(ka) != TCA_PEDIT_KEY_EX) {
68 err = -EINVAL;
69 goto err_out;
70 }
71
72 err = nla_parse_nested(tb, TCA_PEDIT_KEY_EX_MAX, ka,
73 pedit_key_ex_policy, NULL);
74 if (err)
75 goto err_out;
76
77 if (!tb[TCA_PEDIT_KEY_EX_HTYPE] ||
78 !tb[TCA_PEDIT_KEY_EX_CMD]) {
79 err = -EINVAL;
80 goto err_out;
81 }
82
83 k->htype = nla_get_u16(tb[TCA_PEDIT_KEY_EX_HTYPE]);
84 k->cmd = nla_get_u16(tb[TCA_PEDIT_KEY_EX_CMD]);
85
86 if (k->htype > TCA_PEDIT_HDR_TYPE_MAX ||
87 k->cmd > TCA_PEDIT_CMD_MAX) {
88 err = -EINVAL;
89 goto err_out;
90 }
91
92 k++;
93 }
94
95 if (n) {
96 err = -EINVAL;
97 goto err_out;
98 }
99
100 return keys_ex;
101
102err_out:
103 kfree(keys_ex);
104 return ERR_PTR(err);
105}
106
107static int tcf_pedit_key_ex_dump(struct sk_buff *skb,
108 struct tcf_pedit_key_ex *keys_ex, int n)
109{
110 struct nlattr *keys_start = nla_nest_start(skb, TCA_PEDIT_KEYS_EX);
111
112 for (; n > 0; n--) {
113 struct nlattr *key_start;
114
115 key_start = nla_nest_start(skb, TCA_PEDIT_KEY_EX);
116
117 if (nla_put_u16(skb, TCA_PEDIT_KEY_EX_HTYPE, keys_ex->htype) ||
118 nla_put_u16(skb, TCA_PEDIT_KEY_EX_CMD, keys_ex->cmd)) {
119 nlmsg_trim(skb, keys_start);
120 return -EINVAL;
121 }
122
123 nla_nest_end(skb, key_start);
124
125 keys_ex++;
126 }
127
128 nla_nest_end(skb, keys_start);
129
130 return 0;
131}
132
133static int tcf_pedit_init(struct net *net, struct nlattr *nla,
134 struct nlattr *est, struct tc_action **a,
135 int ovr, int bind)
136{
137 struct tc_action_net *tn = net_generic(net, pedit_net_id);
138 struct nlattr *tb[TCA_PEDIT_MAX + 1];
139 struct nlattr *pattr;
140 struct tc_pedit *parm;
141 int ret = 0, err;
142 struct tcf_pedit *p;
143 struct tc_pedit_key *keys = NULL;
144 struct tcf_pedit_key_ex *keys_ex;
145 int ksize;
146
147 if (nla == NULL)
148 return -EINVAL;
149
150 err = nla_parse_nested(tb, TCA_PEDIT_MAX, nla, pedit_policy, NULL);
151 if (err < 0)
152 return err;
153
154 pattr = tb[TCA_PEDIT_PARMS];
155 if (!pattr)
156 pattr = tb[TCA_PEDIT_PARMS_EX];
157 if (!pattr)
158 return -EINVAL;
159
160 parm = nla_data(pattr);
161 ksize = parm->nkeys * sizeof(struct tc_pedit_key);
162 if (nla_len(pattr) < sizeof(*parm) + ksize)
163 return -EINVAL;
164
165 keys_ex = tcf_pedit_keys_ex_parse(tb[TCA_PEDIT_KEYS_EX], parm->nkeys);
166 if (IS_ERR(keys_ex))
167 return PTR_ERR(keys_ex);
168
169 if (!tcf_idr_check(tn, parm->index, a, bind)) {
170 if (!parm->nkeys)
171 return -EINVAL;
172 ret = tcf_idr_create(tn, parm->index, est, a,
173 &act_pedit_ops, bind, false);
174 if (ret)
175 return ret;
176 p = to_pedit(*a);
177 keys = kmalloc(ksize, GFP_KERNEL);
178 if (keys == NULL) {
179 tcf_idr_cleanup(*a, est);
180 kfree(keys_ex);
181 return -ENOMEM;
182 }
183 ret = ACT_P_CREATED;
184 } else {
185 if (bind)
186 return 0;
187 tcf_idr_release(*a, bind);
188 if (!ovr)
189 return -EEXIST;
190 p = to_pedit(*a);
191 if (p->tcfp_nkeys && p->tcfp_nkeys != parm->nkeys) {
192 keys = kmalloc(ksize, GFP_KERNEL);
193 if (!keys) {
194 kfree(keys_ex);
195 return -ENOMEM;
196 }
197 }
198 }
199
200 spin_lock_bh(&p->tcf_lock);
201 p->tcfp_flags = parm->flags;
202 p->tcf_action = parm->action;
203 if (keys) {
204 kfree(p->tcfp_keys);
205 p->tcfp_keys = keys;
206 p->tcfp_nkeys = parm->nkeys;
207 }
208 memcpy(p->tcfp_keys, parm->keys, ksize);
209
210 kfree(p->tcfp_keys_ex);
211 p->tcfp_keys_ex = keys_ex;
212
213 spin_unlock_bh(&p->tcf_lock);
214 if (ret == ACT_P_CREATED)
215 tcf_idr_insert(tn, *a);
216 return ret;
217}
218
219static void tcf_pedit_cleanup(struct tc_action *a, int bind)
220{
221 struct tcf_pedit *p = to_pedit(a);
222 struct tc_pedit_key *keys = p->tcfp_keys;
223 kfree(keys);
224 kfree(p->tcfp_keys_ex);
225}
226
227static bool offset_valid(struct sk_buff *skb, int offset)
228{
229 if (offset > 0 && offset > skb->len)
230 return false;
231
232 if (offset < 0 && -offset > skb_headroom(skb))
233 return false;
234
235 return true;
236}
237
238static int pedit_skb_hdr_offset(struct sk_buff *skb,
239 enum pedit_header_type htype, int *hoffset)
240{
241 int ret = -EINVAL;
242
243 switch (htype) {
244 case TCA_PEDIT_KEY_EX_HDR_TYPE_ETH:
245 if (skb_mac_header_was_set(skb)) {
246 *hoffset = skb_mac_offset(skb);
247 ret = 0;
248 }
249 break;
250 case TCA_PEDIT_KEY_EX_HDR_TYPE_NETWORK:
251 case TCA_PEDIT_KEY_EX_HDR_TYPE_IP4:
252 case TCA_PEDIT_KEY_EX_HDR_TYPE_IP6:
253 *hoffset = skb_network_offset(skb);
254 ret = 0;
255 break;
256 case TCA_PEDIT_KEY_EX_HDR_TYPE_TCP:
257 case TCA_PEDIT_KEY_EX_HDR_TYPE_UDP:
258 if (skb_transport_header_was_set(skb)) {
259 *hoffset = skb_transport_offset(skb);
260 ret = 0;
261 }
262 break;
263 default:
264 ret = -EINVAL;
265 break;
266 };
267
268 return ret;
269}
270
271static int tcf_pedit(struct sk_buff *skb, const struct tc_action *a,
272 struct tcf_result *res)
273{
274 struct tcf_pedit *p = to_pedit(a);
275 int i;
276
277 if (skb_unclone(skb, GFP_ATOMIC))
278 return p->tcf_action;
279
280 spin_lock(&p->tcf_lock);
281
282 tcf_lastuse_update(&p->tcf_tm);
283
284 if (p->tcfp_nkeys > 0) {
285 struct tc_pedit_key *tkey = p->tcfp_keys;
286 struct tcf_pedit_key_ex *tkey_ex = p->tcfp_keys_ex;
287 enum pedit_header_type htype = TCA_PEDIT_KEY_EX_HDR_TYPE_NETWORK;
288 enum pedit_cmd cmd = TCA_PEDIT_KEY_EX_CMD_SET;
289
290 for (i = p->tcfp_nkeys; i > 0; i--, tkey++) {
291 u32 *ptr, _data;
292 int offset = tkey->off;
293 int hoffset;
294 u32 val;
295 int rc;
296
297 if (tkey_ex) {
298 htype = tkey_ex->htype;
299 cmd = tkey_ex->cmd;
300
301 tkey_ex++;
302 }
303
304 rc = pedit_skb_hdr_offset(skb, htype, &hoffset);
305 if (rc) {
306 pr_info("tc filter pedit bad header type specified (0x%x)\n",
307 htype);
308 goto bad;
309 }
310
311 if (tkey->offmask) {
312 char *d, _d;
313
314 if (!offset_valid(skb, hoffset + tkey->at)) {
315 pr_info("tc filter pedit 'at' offset %d out of bounds\n",
316 hoffset + tkey->at);
317 goto bad;
318 }
319 d = skb_header_pointer(skb, hoffset + tkey->at, 1,
320 &_d);
321 if (!d)
322 goto bad;
323 offset += (*d & tkey->offmask) >> tkey->shift;
324 }
325
326 if (offset % 4) {
327 pr_info("tc filter pedit"
328 " offset must be on 32 bit boundaries\n");
329 goto bad;
330 }
331
332 if (!offset_valid(skb, hoffset + offset)) {
333 pr_info("tc filter pedit offset %d out of bounds\n",
334 hoffset + offset);
335 goto bad;
336 }
337
338 ptr = skb_header_pointer(skb, hoffset + offset, 4, &_data);
339 if (!ptr)
340 goto bad;
341
342 switch (cmd) {
343 case TCA_PEDIT_KEY_EX_CMD_SET:
344 val = tkey->val;
345 break;
346 case TCA_PEDIT_KEY_EX_CMD_ADD:
347 val = (*ptr + tkey->val) & ~tkey->mask;
348 break;
349 default:
350 pr_info("tc filter pedit bad command (%d)\n",
351 cmd);
352 goto bad;
353 }
354
355 *ptr = ((*ptr & tkey->mask) ^ val);
356 if (ptr == &_data)
357 skb_store_bits(skb, hoffset + offset, ptr, 4);
358 }
359
360 goto done;
361 } else
362 WARN(1, "pedit BUG: index %d\n", p->tcf_index);
363
364bad:
365 p->tcf_qstats.overlimits++;
366done:
367 bstats_update(&p->tcf_bstats, skb);
368 spin_unlock(&p->tcf_lock);
369 return p->tcf_action;
370}
371
372static int tcf_pedit_dump(struct sk_buff *skb, struct tc_action *a,
373 int bind, int ref)
374{
375 unsigned char *b = skb_tail_pointer(skb);
376 struct tcf_pedit *p = to_pedit(a);
377 struct tc_pedit *opt;
378 struct tcf_t t;
379 int s;
380
381 s = sizeof(*opt) + p->tcfp_nkeys * sizeof(struct tc_pedit_key);
382
383
384 opt = kzalloc(s, GFP_ATOMIC);
385 if (unlikely(!opt))
386 return -ENOBUFS;
387
388 memcpy(opt->keys, p->tcfp_keys,
389 p->tcfp_nkeys * sizeof(struct tc_pedit_key));
390 opt->index = p->tcf_index;
391 opt->nkeys = p->tcfp_nkeys;
392 opt->flags = p->tcfp_flags;
393 opt->action = p->tcf_action;
394 opt->refcnt = p->tcf_refcnt - ref;
395 opt->bindcnt = p->tcf_bindcnt - bind;
396
397 if (p->tcfp_keys_ex) {
398 tcf_pedit_key_ex_dump(skb, p->tcfp_keys_ex, p->tcfp_nkeys);
399
400 if (nla_put(skb, TCA_PEDIT_PARMS_EX, s, opt))
401 goto nla_put_failure;
402 } else {
403 if (nla_put(skb, TCA_PEDIT_PARMS, s, opt))
404 goto nla_put_failure;
405 }
406
407 tcf_tm_dump(&t, &p->tcf_tm);
408 if (nla_put_64bit(skb, TCA_PEDIT_TM, sizeof(t), &t, TCA_PEDIT_PAD))
409 goto nla_put_failure;
410
411 kfree(opt);
412 return skb->len;
413
414nla_put_failure:
415 nlmsg_trim(skb, b);
416 kfree(opt);
417 return -1;
418}
419
420static int tcf_pedit_walker(struct net *net, struct sk_buff *skb,
421 struct netlink_callback *cb, int type,
422 const struct tc_action_ops *ops)
423{
424 struct tc_action_net *tn = net_generic(net, pedit_net_id);
425
426 return tcf_generic_walker(tn, skb, cb, type, ops);
427}
428
429static int tcf_pedit_search(struct net *net, struct tc_action **a, u32 index)
430{
431 struct tc_action_net *tn = net_generic(net, pedit_net_id);
432
433 return tcf_idr_search(tn, a, index);
434}
435
436static struct tc_action_ops act_pedit_ops = {
437 .kind = "pedit",
438 .type = TCA_ACT_PEDIT,
439 .owner = THIS_MODULE,
440 .act = tcf_pedit,
441 .dump = tcf_pedit_dump,
442 .cleanup = tcf_pedit_cleanup,
443 .init = tcf_pedit_init,
444 .walk = tcf_pedit_walker,
445 .lookup = tcf_pedit_search,
446 .size = sizeof(struct tcf_pedit),
447};
448
449static __net_init int pedit_init_net(struct net *net)
450{
451 struct tc_action_net *tn = net_generic(net, pedit_net_id);
452
453 return tc_action_net_init(tn, &act_pedit_ops);
454}
455
456static void __net_exit pedit_exit_net(struct net *net)
457{
458 struct tc_action_net *tn = net_generic(net, pedit_net_id);
459
460 tc_action_net_exit(tn);
461}
462
463static struct pernet_operations pedit_net_ops = {
464 .init = pedit_init_net,
465 .exit = pedit_exit_net,
466 .id = &pedit_net_id,
467 .size = sizeof(struct tc_action_net),
468};
469
470MODULE_AUTHOR("Jamal Hadi Salim(2002-4)");
471MODULE_DESCRIPTION("Generic Packet Editor actions");
472MODULE_LICENSE("GPL");
473
474static int __init pedit_init_module(void)
475{
476 return tcf_register_action(&act_pedit_ops, &pedit_net_ops);
477}
478
479static void __exit pedit_cleanup_module(void)
480{
481 tcf_unregister_action(&act_pedit_ops, &pedit_net_ops);
482}
483
484module_init(pedit_init_module);
485module_exit(pedit_cleanup_module);
486
487
