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]);
53 ksize = parm->nkeys * sizeof(struct tc_pedit_key);
54 if (nla_len(tb[TCA_PEDIT_PARMS]) < sizeof(*parm) + ksize)
57 if (!tcf_hash_check(parm->index, a, bind)) {
60 ret = tcf_hash_create(parm->index, est, a, sizeof(*p),
65 keys = kmalloc(ksize, GFP_KERNEL);
67 tcf_hash_cleanup(a, est);
74 tcf_hash_release(a, bind);
78 if (p->tcfp_nkeys && p->tcfp_nkeys != parm->nkeys) {
79 keys = kmalloc(ksize, GFP_KERNEL);
85 spin_lock_bh(&p->tcf_lock);
86 p->tcfp_flags = parm->flags;
87 p->tcf_action = parm->action;
91 p->tcfp_nkeys = parm->nkeys;
93 memcpy(p->tcfp_keys, parm->keys, ksize);
94 spin_unlock_bh(&p->tcf_lock);
95 if (ret == ACT_P_CREATED)
100 static void tcf_pedit_cleanup(struct tc_action *a, int bind)
102 struct tcf_pedit *p = a->priv;
103 struct tc_pedit_key *keys = p->tcfp_keys;
107 static bool offset_valid(struct sk_buff *skb, int offset)
109 if (offset > 0 && offset > skb->len)
112 if (offset < 0 && -offset > skb_headroom(skb))
118 static int tcf_pedit(struct sk_buff *skb, const struct tc_action *a,
119 struct tcf_result *res)
121 struct tcf_pedit *p = a->priv;
125 if (skb_unclone(skb, GFP_ATOMIC))
126 return p->tcf_action;
128 off = skb_network_offset(skb);
130 spin_lock(&p->tcf_lock);
132 p->tcf_tm.lastuse = jiffies;
134 if (p->tcfp_nkeys > 0) {
135 struct tc_pedit_key *tkey = p->tcfp_keys;
137 for (i = p->tcfp_nkeys; i > 0; i--, tkey++) {
139 int offset = tkey->off;
144 if (!offset_valid(skb, off + tkey->at)) {
145 pr_info("tc filter pedit 'at' offset %d out of bounds\n",
149 d = skb_header_pointer(skb, off + tkey->at, 1,
153 offset += (*d & tkey->offmask) >> tkey->shift;
157 pr_info("tc filter pedit"
158 " offset must be on 32 bit boundaries\n");
162 if (!offset_valid(skb, off + offset)) {
163 pr_info("tc filter pedit offset %d out of bounds\n",
168 ptr = skb_header_pointer(skb, off + offset, 4, &_data);
171 /* just do it, baby */
172 *ptr = ((*ptr & tkey->mask) ^ tkey->val);
174 skb_store_bits(skb, off + offset, ptr, 4);
179 WARN(1, "pedit BUG: index %d\n", p->tcf_index);
182 p->tcf_qstats.overlimits++;
184 bstats_update(&p->tcf_bstats, skb);
185 spin_unlock(&p->tcf_lock);
186 return p->tcf_action;
189 static int tcf_pedit_dump(struct sk_buff *skb, struct tc_action *a,
192 unsigned char *b = skb_tail_pointer(skb);
193 struct tcf_pedit *p = a->priv;
194 struct tc_pedit *opt;
198 s = sizeof(*opt) + p->tcfp_nkeys * sizeof(struct tc_pedit_key);
200 /* netlink spinlocks held above us - must use ATOMIC */
201 opt = kzalloc(s, GFP_ATOMIC);
205 memcpy(opt->keys, p->tcfp_keys,
206 p->tcfp_nkeys * sizeof(struct tc_pedit_key));
207 opt->index = p->tcf_index;
208 opt->nkeys = p->tcfp_nkeys;
209 opt->flags = p->tcfp_flags;
210 opt->action = p->tcf_action;
211 opt->refcnt = p->tcf_refcnt - ref;
212 opt->bindcnt = p->tcf_bindcnt - bind;
214 if (nla_put(skb, TCA_PEDIT_PARMS, s, opt))
215 goto nla_put_failure;
216 t.install = jiffies_to_clock_t(jiffies - p->tcf_tm.install);
217 t.lastuse = jiffies_to_clock_t(jiffies - p->tcf_tm.lastuse);
218 t.expires = jiffies_to_clock_t(p->tcf_tm.expires);
219 if (nla_put(skb, TCA_PEDIT_TM, sizeof(t), &t))
220 goto nla_put_failure;
230 static struct tc_action_ops act_pedit_ops = {
232 .type = TCA_ACT_PEDIT,
233 .owner = THIS_MODULE,
235 .dump = tcf_pedit_dump,
236 .cleanup = tcf_pedit_cleanup,
237 .init = tcf_pedit_init,
240 MODULE_AUTHOR("Jamal Hadi Salim(2002-4)");
241 MODULE_DESCRIPTION("Generic Packet Editor actions");
242 MODULE_LICENSE("GPL");
244 static int __init pedit_init_module(void)
246 return tcf_register_action(&act_pedit_ops, PEDIT_TAB_MASK);
249 static void __exit pedit_cleanup_module(void)
251 tcf_unregister_action(&act_pedit_ops);
254 module_init(pedit_init_module);
255 module_exit(pedit_cleanup_module);