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, u32 flags,
141 struct netlink_ext_ack *extack)
143 struct tc_action_net *tn = net_generic(net, pedit_net_id);
144 struct nlattr *tb[TCA_PEDIT_MAX + 1];
145 struct tcf_chain *goto_ch = NULL;
146 struct tc_pedit_key *keys = NULL;
147 struct tcf_pedit_key_ex *keys_ex;
148 struct tc_pedit *parm;
149 struct nlattr *pattr;
156 NL_SET_ERR_MSG_MOD(extack, "Pedit requires attributes to be passed");
160 err = nla_parse_nested_deprecated(tb, TCA_PEDIT_MAX, nla,
165 pattr = tb[TCA_PEDIT_PARMS];
167 pattr = tb[TCA_PEDIT_PARMS_EX];
169 NL_SET_ERR_MSG_MOD(extack, "Missing required TCA_PEDIT_PARMS or TCA_PEDIT_PARMS_EX pedit attribute");
173 parm = nla_data(pattr);
175 NL_SET_ERR_MSG_MOD(extack, "Pedit requires keys to be passed");
178 ksize = parm->nkeys * sizeof(struct tc_pedit_key);
179 if (nla_len(pattr) < sizeof(*parm) + ksize) {
180 NL_SET_ERR_MSG_ATTR(extack, pattr, "Length of TCA_PEDIT_PARMS or TCA_PEDIT_PARMS_EX pedit attribute is invalid");
184 keys_ex = tcf_pedit_keys_ex_parse(tb[TCA_PEDIT_KEYS_EX], parm->nkeys);
186 return PTR_ERR(keys_ex);
189 err = tcf_idr_check_alloc(tn, &index, a, bind);
191 ret = tcf_idr_create(tn, index, est, a,
192 &act_pedit_ops, bind, false, 0);
194 tcf_idr_cleanup(tn, index);
198 } else if (err > 0) {
210 err = tcf_action_check_ctrlact(parm->action, tp, &goto_ch, extack);
216 spin_lock_bh(&p->tcf_lock);
218 if (ret == ACT_P_CREATED ||
219 (p->tcfp_nkeys && p->tcfp_nkeys != parm->nkeys)) {
220 keys = kmalloc(ksize, GFP_ATOMIC);
222 spin_unlock_bh(&p->tcf_lock);
228 p->tcfp_nkeys = parm->nkeys;
230 memcpy(p->tcfp_keys, parm->keys, ksize);
232 p->tcfp_flags = parm->flags;
233 goto_ch = tcf_action_set_ctrlact(*a, parm->action, goto_ch);
235 kfree(p->tcfp_keys_ex);
236 p->tcfp_keys_ex = keys_ex;
238 spin_unlock_bh(&p->tcf_lock);
240 tcf_chain_put_by_act(goto_ch);
241 if (ret == ACT_P_CREATED)
242 tcf_idr_insert(tn, *a);
247 tcf_chain_put_by_act(goto_ch);
249 tcf_idr_release(*a, bind);
256 static void tcf_pedit_cleanup(struct tc_action *a)
258 struct tcf_pedit *p = to_pedit(a);
259 struct tc_pedit_key *keys = p->tcfp_keys;
262 kfree(p->tcfp_keys_ex);
265 static bool offset_valid(struct sk_buff *skb, int offset)
267 if (offset > 0 && offset > skb->len)
270 if (offset < 0 && -offset > skb_headroom(skb))
276 static int pedit_skb_hdr_offset(struct sk_buff *skb,
277 enum pedit_header_type htype, int *hoffset)
282 case TCA_PEDIT_KEY_EX_HDR_TYPE_ETH:
283 if (skb_mac_header_was_set(skb)) {
284 *hoffset = skb_mac_offset(skb);
288 case TCA_PEDIT_KEY_EX_HDR_TYPE_NETWORK:
289 case TCA_PEDIT_KEY_EX_HDR_TYPE_IP4:
290 case TCA_PEDIT_KEY_EX_HDR_TYPE_IP6:
291 *hoffset = skb_network_offset(skb);
294 case TCA_PEDIT_KEY_EX_HDR_TYPE_TCP:
295 case TCA_PEDIT_KEY_EX_HDR_TYPE_UDP:
296 if (skb_transport_header_was_set(skb)) {
297 *hoffset = skb_transport_offset(skb);
309 static int tcf_pedit_act(struct sk_buff *skb, const struct tc_action *a,
310 struct tcf_result *res)
312 struct tcf_pedit *p = to_pedit(a);
315 if (skb_unclone(skb, GFP_ATOMIC))
316 return p->tcf_action;
318 spin_lock(&p->tcf_lock);
320 tcf_lastuse_update(&p->tcf_tm);
322 if (p->tcfp_nkeys > 0) {
323 struct tc_pedit_key *tkey = p->tcfp_keys;
324 struct tcf_pedit_key_ex *tkey_ex = p->tcfp_keys_ex;
325 enum pedit_header_type htype =
326 TCA_PEDIT_KEY_EX_HDR_TYPE_NETWORK;
327 enum pedit_cmd cmd = TCA_PEDIT_KEY_EX_CMD_SET;
329 for (i = p->tcfp_nkeys; i > 0; i--, tkey++) {
331 int offset = tkey->off;
337 htype = tkey_ex->htype;
343 rc = pedit_skb_hdr_offset(skb, htype, &hoffset);
345 pr_info("tc action pedit bad header type specified (0x%x)\n",
353 if (!offset_valid(skb, hoffset + tkey->at)) {
354 pr_info("tc action pedit 'at' offset %d out of bounds\n",
358 d = skb_header_pointer(skb, hoffset + tkey->at,
362 offset += (*d & tkey->offmask) >> tkey->shift;
366 pr_info("tc action pedit offset must be on 32 bit boundaries\n");
370 if (!offset_valid(skb, hoffset + offset)) {
371 pr_info("tc action pedit offset %d out of bounds\n",
376 ptr = skb_header_pointer(skb, hoffset + offset,
377 sizeof(hdata), &hdata);
380 /* just do it, baby */
382 case TCA_PEDIT_KEY_EX_CMD_SET:
385 case TCA_PEDIT_KEY_EX_CMD_ADD:
386 val = (*ptr + tkey->val) & ~tkey->mask;
389 pr_info("tc action pedit bad command (%d)\n",
394 *ptr = ((*ptr & tkey->mask) ^ val);
396 skb_store_bits(skb, hoffset + offset, ptr, 4);
401 WARN(1, "pedit BUG: index %d\n", p->tcf_index);
405 p->tcf_qstats.overlimits++;
407 bstats_update(&p->tcf_bstats, skb);
408 spin_unlock(&p->tcf_lock);
409 return p->tcf_action;
412 static int tcf_pedit_dump(struct sk_buff *skb, struct tc_action *a,
415 unsigned char *b = skb_tail_pointer(skb);
416 struct tcf_pedit *p = to_pedit(a);
417 struct tc_pedit *opt;
421 s = struct_size(opt, keys, p->tcfp_nkeys);
423 /* netlink spinlocks held above us - must use ATOMIC */
424 opt = kzalloc(s, GFP_ATOMIC);
428 spin_lock_bh(&p->tcf_lock);
429 memcpy(opt->keys, p->tcfp_keys,
430 p->tcfp_nkeys * sizeof(struct tc_pedit_key));
431 opt->index = p->tcf_index;
432 opt->nkeys = p->tcfp_nkeys;
433 opt->flags = p->tcfp_flags;
434 opt->action = p->tcf_action;
435 opt->refcnt = refcount_read(&p->tcf_refcnt) - ref;
436 opt->bindcnt = atomic_read(&p->tcf_bindcnt) - bind;
438 if (p->tcfp_keys_ex) {
439 if (tcf_pedit_key_ex_dump(skb,
442 goto nla_put_failure;
444 if (nla_put(skb, TCA_PEDIT_PARMS_EX, s, opt))
445 goto nla_put_failure;
447 if (nla_put(skb, TCA_PEDIT_PARMS, s, opt))
448 goto nla_put_failure;
451 tcf_tm_dump(&t, &p->tcf_tm);
452 if (nla_put_64bit(skb, TCA_PEDIT_TM, sizeof(t), &t, TCA_PEDIT_PAD))
453 goto nla_put_failure;
454 spin_unlock_bh(&p->tcf_lock);
460 spin_unlock_bh(&p->tcf_lock);
466 static int tcf_pedit_walker(struct net *net, struct sk_buff *skb,
467 struct netlink_callback *cb, int type,
468 const struct tc_action_ops *ops,
469 struct netlink_ext_ack *extack)
471 struct tc_action_net *tn = net_generic(net, pedit_net_id);
473 return tcf_generic_walker(tn, skb, cb, type, ops, extack);
476 static int tcf_pedit_search(struct net *net, struct tc_action **a, u32 index)
478 struct tc_action_net *tn = net_generic(net, pedit_net_id);
480 return tcf_idr_search(tn, a, index);
483 static struct tc_action_ops act_pedit_ops = {
486 .owner = THIS_MODULE,
487 .act = tcf_pedit_act,
488 .dump = tcf_pedit_dump,
489 .cleanup = tcf_pedit_cleanup,
490 .init = tcf_pedit_init,
491 .walk = tcf_pedit_walker,
492 .lookup = tcf_pedit_search,
493 .size = sizeof(struct tcf_pedit),
496 static __net_init int pedit_init_net(struct net *net)
498 struct tc_action_net *tn = net_generic(net, pedit_net_id);
500 return tc_action_net_init(net, tn, &act_pedit_ops);
503 static void __net_exit pedit_exit_net(struct list_head *net_list)
505 tc_action_net_exit(net_list, pedit_net_id);
508 static struct pernet_operations pedit_net_ops = {
509 .init = pedit_init_net,
510 .exit_batch = pedit_exit_net,
512 .size = sizeof(struct tc_action_net),
515 MODULE_AUTHOR("Jamal Hadi Salim(2002-4)");
516 MODULE_DESCRIPTION("Generic Packet Editor actions");
517 MODULE_LICENSE("GPL");
519 static int __init pedit_init_module(void)
521 return tcf_register_action(&act_pedit_ops, &pedit_net_ops);
524 static void __exit pedit_cleanup_module(void)
526 tcf_unregister_action(&act_pedit_ops, &pedit_net_ops);
529 module_init(pedit_init_module);
530 module_exit(pedit_cleanup_module);