1 // SPDX-License-Identifier: GPL-2.0-or-later
3 * net/sched/act_pedit.c Generic packet editor
5 * Authors: Jamal Hadi Salim (2002-4)
8 #include <linux/types.h>
9 #include <linux/kernel.h>
10 #include <linux/string.h>
11 #include <linux/errno.h>
12 #include <linux/skbuff.h>
13 #include <linux/rtnetlink.h>
14 #include <linux/module.h>
15 #include <linux/init.h>
16 #include <linux/slab.h>
17 #include <net/netlink.h>
18 #include <net/pkt_sched.h>
19 #include <linux/tc_act/tc_pedit.h>
20 #include <net/tc_act/tc_pedit.h>
21 #include <uapi/linux/tc_act/tc_pedit.h>
22 #include <net/pkt_cls.h>
24 static unsigned int pedit_net_id;
25 static struct tc_action_ops act_pedit_ops;
27 static const struct nla_policy pedit_policy[TCA_PEDIT_MAX + 1] = {
28 [TCA_PEDIT_PARMS] = { .len = sizeof(struct tc_pedit) },
29 [TCA_PEDIT_KEYS_EX] = { .type = NLA_NESTED },
32 static const struct nla_policy pedit_key_ex_policy[TCA_PEDIT_KEY_EX_MAX + 1] = {
33 [TCA_PEDIT_KEY_EX_HTYPE] = { .type = NLA_U16 },
34 [TCA_PEDIT_KEY_EX_CMD] = { .type = NLA_U16 },
37 static struct tcf_pedit_key_ex *tcf_pedit_keys_ex_parse(struct nlattr *nla,
40 struct tcf_pedit_key_ex *keys_ex;
41 struct tcf_pedit_key_ex *k;
42 const struct nlattr *ka;
49 keys_ex = kcalloc(n, sizeof(*k), GFP_KERNEL);
51 return ERR_PTR(-ENOMEM);
55 nla_for_each_nested(ka, nla, rem) {
56 struct nlattr *tb[TCA_PEDIT_KEY_EX_MAX + 1];
64 if (nla_type(ka) != TCA_PEDIT_KEY_EX) {
69 err = nla_parse_nested_deprecated(tb, TCA_PEDIT_KEY_EX_MAX,
70 ka, pedit_key_ex_policy,
75 if (!tb[TCA_PEDIT_KEY_EX_HTYPE] ||
76 !tb[TCA_PEDIT_KEY_EX_CMD]) {
81 k->htype = nla_get_u16(tb[TCA_PEDIT_KEY_EX_HTYPE]);
82 k->cmd = nla_get_u16(tb[TCA_PEDIT_KEY_EX_CMD]);
84 if (k->htype > TCA_PEDIT_HDR_TYPE_MAX ||
85 k->cmd > TCA_PEDIT_CMD_MAX) {
105 static int tcf_pedit_key_ex_dump(struct sk_buff *skb,
106 struct tcf_pedit_key_ex *keys_ex, int n)
108 struct nlattr *keys_start = nla_nest_start_noflag(skb,
114 struct nlattr *key_start;
116 key_start = nla_nest_start_noflag(skb, TCA_PEDIT_KEY_EX);
120 if (nla_put_u16(skb, TCA_PEDIT_KEY_EX_HTYPE, keys_ex->htype) ||
121 nla_put_u16(skb, TCA_PEDIT_KEY_EX_CMD, keys_ex->cmd))
124 nla_nest_end(skb, key_start);
129 nla_nest_end(skb, keys_start);
133 nla_nest_cancel(skb, keys_start);
137 static int tcf_pedit_init(struct net *net, struct nlattr *nla,
138 struct nlattr *est, struct tc_action **a,
139 int ovr, int bind, bool rtnl_held,
140 struct tcf_proto *tp, struct netlink_ext_ack *extack)
142 struct tc_action_net *tn = net_generic(net, pedit_net_id);
143 struct nlattr *tb[TCA_PEDIT_MAX + 1];
144 struct tcf_chain *goto_ch = NULL;
145 struct tc_pedit_key *keys = NULL;
146 struct tcf_pedit_key_ex *keys_ex;
147 struct tc_pedit *parm;
148 struct nlattr *pattr;
155 NL_SET_ERR_MSG_MOD(extack, "Pedit requires attributes to be passed");
159 err = nla_parse_nested_deprecated(tb, TCA_PEDIT_MAX, nla,
164 pattr = tb[TCA_PEDIT_PARMS];
166 pattr = tb[TCA_PEDIT_PARMS_EX];
168 NL_SET_ERR_MSG_MOD(extack, "Missing required TCA_PEDIT_PARMS or TCA_PEDIT_PARMS_EX pedit attribute");
172 parm = nla_data(pattr);
173 ksize = parm->nkeys * sizeof(struct tc_pedit_key);
174 if (nla_len(pattr) < sizeof(*parm) + ksize) {
175 NL_SET_ERR_MSG_ATTR(extack, pattr, "Length of TCA_PEDIT_PARMS or TCA_PEDIT_PARMS_EX pedit attribute is invalid");
179 keys_ex = tcf_pedit_keys_ex_parse(tb[TCA_PEDIT_KEYS_EX], parm->nkeys);
181 return PTR_ERR(keys_ex);
184 err = tcf_idr_check_alloc(tn, &index, a, bind);
187 tcf_idr_cleanup(tn, index);
188 NL_SET_ERR_MSG_MOD(extack, "Pedit requires keys to be passed");
192 ret = tcf_idr_create(tn, index, est, a,
193 &act_pedit_ops, bind, false);
195 tcf_idr_cleanup(tn, index);
199 } else if (err > 0) {
211 err = tcf_action_check_ctrlact(parm->action, tp, &goto_ch, extack);
217 spin_lock_bh(&p->tcf_lock);
219 if (ret == ACT_P_CREATED ||
220 (p->tcfp_nkeys && p->tcfp_nkeys != parm->nkeys)) {
221 keys = kmalloc(ksize, GFP_ATOMIC);
223 spin_unlock_bh(&p->tcf_lock);
229 p->tcfp_nkeys = parm->nkeys;
231 memcpy(p->tcfp_keys, parm->keys, ksize);
233 p->tcfp_flags = parm->flags;
234 goto_ch = tcf_action_set_ctrlact(*a, parm->action, goto_ch);
236 kfree(p->tcfp_keys_ex);
237 p->tcfp_keys_ex = keys_ex;
239 spin_unlock_bh(&p->tcf_lock);
241 tcf_chain_put_by_act(goto_ch);
242 if (ret == ACT_P_CREATED)
243 tcf_idr_insert(tn, *a);
248 tcf_chain_put_by_act(goto_ch);
250 tcf_idr_release(*a, bind);
257 static void tcf_pedit_cleanup(struct tc_action *a)
259 struct tcf_pedit *p = to_pedit(a);
260 struct tc_pedit_key *keys = p->tcfp_keys;
263 kfree(p->tcfp_keys_ex);
266 static bool offset_valid(struct sk_buff *skb, int offset)
268 if (offset > 0 && offset > skb->len)
271 if (offset < 0 && -offset > skb_headroom(skb))
277 static int pedit_skb_hdr_offset(struct sk_buff *skb,
278 enum pedit_header_type htype, int *hoffset)
283 case TCA_PEDIT_KEY_EX_HDR_TYPE_ETH:
284 if (skb_mac_header_was_set(skb)) {
285 *hoffset = skb_mac_offset(skb);
289 case TCA_PEDIT_KEY_EX_HDR_TYPE_NETWORK:
290 case TCA_PEDIT_KEY_EX_HDR_TYPE_IP4:
291 case TCA_PEDIT_KEY_EX_HDR_TYPE_IP6:
292 *hoffset = skb_network_offset(skb);
295 case TCA_PEDIT_KEY_EX_HDR_TYPE_TCP:
296 case TCA_PEDIT_KEY_EX_HDR_TYPE_UDP:
297 if (skb_transport_header_was_set(skb)) {
298 *hoffset = skb_transport_offset(skb);
310 static int tcf_pedit_act(struct sk_buff *skb, const struct tc_action *a,
311 struct tcf_result *res)
313 struct tcf_pedit *p = to_pedit(a);
316 if (skb_unclone(skb, GFP_ATOMIC))
317 return p->tcf_action;
319 spin_lock(&p->tcf_lock);
321 tcf_lastuse_update(&p->tcf_tm);
323 if (p->tcfp_nkeys > 0) {
324 struct tc_pedit_key *tkey = p->tcfp_keys;
325 struct tcf_pedit_key_ex *tkey_ex = p->tcfp_keys_ex;
326 enum pedit_header_type htype =
327 TCA_PEDIT_KEY_EX_HDR_TYPE_NETWORK;
328 enum pedit_cmd cmd = TCA_PEDIT_KEY_EX_CMD_SET;
330 for (i = p->tcfp_nkeys; i > 0; i--, tkey++) {
332 int offset = tkey->off;
338 htype = tkey_ex->htype;
344 rc = pedit_skb_hdr_offset(skb, htype, &hoffset);
346 pr_info("tc action pedit bad header type specified (0x%x)\n",
354 if (!offset_valid(skb, hoffset + tkey->at)) {
355 pr_info("tc action pedit 'at' offset %d out of bounds\n",
359 d = skb_header_pointer(skb, hoffset + tkey->at,
363 offset += (*d & tkey->offmask) >> tkey->shift;
367 pr_info("tc action pedit offset must be on 32 bit boundaries\n");
371 if (!offset_valid(skb, hoffset + offset)) {
372 pr_info("tc action pedit offset %d out of bounds\n",
377 ptr = skb_header_pointer(skb, hoffset + offset,
378 sizeof(hdata), &hdata);
381 /* just do it, baby */
383 case TCA_PEDIT_KEY_EX_CMD_SET:
386 case TCA_PEDIT_KEY_EX_CMD_ADD:
387 val = (*ptr + tkey->val) & ~tkey->mask;
390 pr_info("tc action pedit bad command (%d)\n",
395 *ptr = ((*ptr & tkey->mask) ^ val);
397 skb_store_bits(skb, hoffset + offset, ptr, 4);
402 WARN(1, "pedit BUG: index %d\n", p->tcf_index);
406 p->tcf_qstats.overlimits++;
408 bstats_update(&p->tcf_bstats, skb);
409 spin_unlock(&p->tcf_lock);
410 return p->tcf_action;
413 static int tcf_pedit_dump(struct sk_buff *skb, struct tc_action *a,
416 unsigned char *b = skb_tail_pointer(skb);
417 struct tcf_pedit *p = to_pedit(a);
418 struct tc_pedit *opt;
422 s = struct_size(opt, keys, p->tcfp_nkeys);
424 /* netlink spinlocks held above us - must use ATOMIC */
425 opt = kzalloc(s, GFP_ATOMIC);
429 spin_lock_bh(&p->tcf_lock);
430 memcpy(opt->keys, p->tcfp_keys,
431 p->tcfp_nkeys * sizeof(struct tc_pedit_key));
432 opt->index = p->tcf_index;
433 opt->nkeys = p->tcfp_nkeys;
434 opt->flags = p->tcfp_flags;
435 opt->action = p->tcf_action;
436 opt->refcnt = refcount_read(&p->tcf_refcnt) - ref;
437 opt->bindcnt = atomic_read(&p->tcf_bindcnt) - bind;
439 if (p->tcfp_keys_ex) {
440 if (tcf_pedit_key_ex_dump(skb,
443 goto nla_put_failure;
445 if (nla_put(skb, TCA_PEDIT_PARMS_EX, s, opt))
446 goto nla_put_failure;
448 if (nla_put(skb, TCA_PEDIT_PARMS, s, opt))
449 goto nla_put_failure;
452 tcf_tm_dump(&t, &p->tcf_tm);
453 if (nla_put_64bit(skb, TCA_PEDIT_TM, sizeof(t), &t, TCA_PEDIT_PAD))
454 goto nla_put_failure;
455 spin_unlock_bh(&p->tcf_lock);
461 spin_unlock_bh(&p->tcf_lock);
467 static int tcf_pedit_walker(struct net *net, struct sk_buff *skb,
468 struct netlink_callback *cb, int type,
469 const struct tc_action_ops *ops,
470 struct netlink_ext_ack *extack)
472 struct tc_action_net *tn = net_generic(net, pedit_net_id);
474 return tcf_generic_walker(tn, skb, cb, type, ops, extack);
477 static int tcf_pedit_search(struct net *net, struct tc_action **a, u32 index)
479 struct tc_action_net *tn = net_generic(net, pedit_net_id);
481 return tcf_idr_search(tn, a, index);
484 static struct tc_action_ops act_pedit_ops = {
487 .owner = THIS_MODULE,
488 .act = tcf_pedit_act,
489 .dump = tcf_pedit_dump,
490 .cleanup = tcf_pedit_cleanup,
491 .init = tcf_pedit_init,
492 .walk = tcf_pedit_walker,
493 .lookup = tcf_pedit_search,
494 .size = sizeof(struct tcf_pedit),
497 static __net_init int pedit_init_net(struct net *net)
499 struct tc_action_net *tn = net_generic(net, pedit_net_id);
501 return tc_action_net_init(tn, &act_pedit_ops);
504 static void __net_exit pedit_exit_net(struct list_head *net_list)
506 tc_action_net_exit(net_list, pedit_net_id);
509 static struct pernet_operations pedit_net_ops = {
510 .init = pedit_init_net,
511 .exit_batch = pedit_exit_net,
513 .size = sizeof(struct tc_action_net),
516 MODULE_AUTHOR("Jamal Hadi Salim(2002-4)");
517 MODULE_DESCRIPTION("Generic Packet Editor actions");
518 MODULE_LICENSE("GPL");
520 static int __init pedit_init_module(void)
522 return tcf_register_action(&act_pedit_ops, &pedit_net_ops);
525 static void __exit pedit_cleanup_module(void)
527 tcf_unregister_action(&act_pedit_ops, &pedit_net_ops);
530 module_init(pedit_init_module);
531 module_exit(pedit_cleanup_module);