2 * net/sched/act_pedit.c Generic packet editor
4 * This program is free software; you can redistribute it and/or
5 * modify it under the terms of the GNU General Public License
6 * as published by the Free Software Foundation; either version
7 * 2 of the License, or (at your option) any later version.
9 * Authors: Jamal Hadi Salim (2002-4)
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>
26 #define PEDIT_TAB_MASK 15
28 static const struct nla_policy pedit_policy[TCA_PEDIT_MAX + 1] = {
29 [TCA_PEDIT_PARMS] = { .len = sizeof(struct tc_pedit) },
32 static int tcf_pedit_init(struct net *net, struct nlattr *nla,
33 struct nlattr *est, struct tc_action *a,
36 struct nlattr *tb[TCA_PEDIT_MAX + 1];
37 struct tc_pedit *parm;
40 struct tc_pedit_key *keys = NULL;
46 err = nla_parse_nested(tb, TCA_PEDIT_MAX, nla, pedit_policy);
50 if (tb[TCA_PEDIT_PARMS] == NULL)
52 parm = nla_data(tb[TCA_PEDIT_PARMS]);
56 ksize = parm->nkeys * sizeof(struct tc_pedit_key);
57 if (nla_len(tb[TCA_PEDIT_PARMS]) < sizeof(*parm) + ksize)
60 if (!tcf_hash_check(parm->index, a, bind)) {
61 ret = tcf_hash_create(parm->index, est, a, sizeof(*p),
66 keys = kmalloc(ksize, GFP_KERNEL);
68 tcf_hash_cleanup(a, est);
75 tcf_hash_release(a, bind);
79 if (p->tcfp_nkeys && p->tcfp_nkeys != parm->nkeys) {
80 keys = kmalloc(ksize, GFP_KERNEL);
86 spin_lock_bh(&p->tcf_lock);
87 p->tcfp_flags = parm->flags;
88 p->tcf_action = parm->action;
92 p->tcfp_nkeys = parm->nkeys;
94 memcpy(p->tcfp_keys, parm->keys, ksize);
95 spin_unlock_bh(&p->tcf_lock);
96 if (ret == ACT_P_CREATED)
101 static void tcf_pedit_cleanup(struct tc_action *a, int bind)
103 struct tcf_pedit *p = a->priv;
104 struct tc_pedit_key *keys = p->tcfp_keys;
108 static bool offset_valid(struct sk_buff *skb, int offset)
110 if (offset > 0 && offset > skb->len)
113 if (offset < 0 && -offset > skb_headroom(skb))
119 static int tcf_pedit(struct sk_buff *skb, const struct tc_action *a,
120 struct tcf_result *res)
122 struct tcf_pedit *p = a->priv;
126 if (skb_unclone(skb, GFP_ATOMIC))
127 return p->tcf_action;
129 off = skb_network_offset(skb);
131 spin_lock(&p->tcf_lock);
133 p->tcf_tm.lastuse = jiffies;
135 if (p->tcfp_nkeys > 0) {
136 struct tc_pedit_key *tkey = p->tcfp_keys;
138 for (i = p->tcfp_nkeys; i > 0; i--, tkey++) {
140 int offset = tkey->off;
145 if (!offset_valid(skb, off + tkey->at)) {
146 pr_info("tc filter pedit 'at' offset %d out of bounds\n",
150 d = skb_header_pointer(skb, off + tkey->at, 1,
154 offset += (*d & tkey->offmask) >> tkey->shift;
158 pr_info("tc filter pedit"
159 " offset must be on 32 bit boundaries\n");
163 if (!offset_valid(skb, off + offset)) {
164 pr_info("tc filter pedit offset %d out of bounds\n",
169 ptr = skb_header_pointer(skb, off + offset, 4, &_data);
172 /* just do it, baby */
173 *ptr = ((*ptr & tkey->mask) ^ tkey->val);
175 skb_store_bits(skb, off + offset, ptr, 4);
180 WARN(1, "pedit BUG: index %d\n", p->tcf_index);
183 p->tcf_qstats.overlimits++;
185 bstats_update(&p->tcf_bstats, skb);
186 spin_unlock(&p->tcf_lock);
187 return p->tcf_action;
190 static int tcf_pedit_dump(struct sk_buff *skb, struct tc_action *a,
193 unsigned char *b = skb_tail_pointer(skb);
194 struct tcf_pedit *p = a->priv;
195 struct tc_pedit *opt;
199 s = sizeof(*opt) + p->tcfp_nkeys * sizeof(struct tc_pedit_key);
201 /* netlink spinlocks held above us - must use ATOMIC */
202 opt = kzalloc(s, GFP_ATOMIC);
206 memcpy(opt->keys, p->tcfp_keys,
207 p->tcfp_nkeys * sizeof(struct tc_pedit_key));
208 opt->index = p->tcf_index;
209 opt->nkeys = p->tcfp_nkeys;
210 opt->flags = p->tcfp_flags;
211 opt->action = p->tcf_action;
212 opt->refcnt = p->tcf_refcnt - ref;
213 opt->bindcnt = p->tcf_bindcnt - bind;
215 if (nla_put(skb, TCA_PEDIT_PARMS, s, opt))
216 goto nla_put_failure;
217 t.install = jiffies_to_clock_t(jiffies - p->tcf_tm.install);
218 t.lastuse = jiffies_to_clock_t(jiffies - p->tcf_tm.lastuse);
219 t.expires = jiffies_to_clock_t(p->tcf_tm.expires);
220 if (nla_put(skb, TCA_PEDIT_TM, sizeof(t), &t))
221 goto nla_put_failure;
231 static struct tc_action_ops act_pedit_ops = {
233 .type = TCA_ACT_PEDIT,
234 .owner = THIS_MODULE,
236 .dump = tcf_pedit_dump,
237 .cleanup = tcf_pedit_cleanup,
238 .init = tcf_pedit_init,
241 MODULE_AUTHOR("Jamal Hadi Salim(2002-4)");
242 MODULE_DESCRIPTION("Generic Packet Editor actions");
243 MODULE_LICENSE("GPL");
245 static int __init pedit_init_module(void)
247 return tcf_register_action(&act_pedit_ops, PEDIT_TAB_MASK);
250 static void __exit pedit_cleanup_module(void)
252 tcf_unregister_action(&act_pedit_ops);
255 module_init(pedit_init_module);
256 module_exit(pedit_cleanup_module);