net_sched: factorize qdisc stats handling
[linux-2.6.git] / net / sched / act_pedit.c
1 /*
2  * net/sched/pedit.c    Generic packet editor
3  *
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.
8  *
9  * Authors:     Jamal Hadi Salim (2002-4)
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
26 #define PEDIT_TAB_MASK  15
27 static struct tcf_common *tcf_pedit_ht[PEDIT_TAB_MASK + 1];
28 static u32 pedit_idx_gen;
29 static DEFINE_RWLOCK(pedit_lock);
30
31 static struct tcf_hashinfo pedit_hash_info = {
32         .htab   =       tcf_pedit_ht,
33         .hmask  =       PEDIT_TAB_MASK,
34         .lock   =       &pedit_lock,
35 };
36
37 static const struct nla_policy pedit_policy[TCA_PEDIT_MAX + 1] = {
38         [TCA_PEDIT_PARMS]       = { .len = sizeof(struct tc_pedit) },
39 };
40
41 static int tcf_pedit_init(struct nlattr *nla, struct nlattr *est,
42                           struct tc_action *a, int ovr, int bind)
43 {
44         struct nlattr *tb[TCA_PEDIT_MAX + 1];
45         struct tc_pedit *parm;
46         int ret = 0, err;
47         struct tcf_pedit *p;
48         struct tcf_common *pc;
49         struct tc_pedit_key *keys = NULL;
50         int ksize;
51
52         if (nla == NULL)
53                 return -EINVAL;
54
55         err = nla_parse_nested(tb, TCA_PEDIT_MAX, nla, pedit_policy);
56         if (err < 0)
57                 return err;
58
59         if (tb[TCA_PEDIT_PARMS] == NULL)
60                 return -EINVAL;
61         parm = nla_data(tb[TCA_PEDIT_PARMS]);
62         ksize = parm->nkeys * sizeof(struct tc_pedit_key);
63         if (nla_len(tb[TCA_PEDIT_PARMS]) < sizeof(*parm) + ksize)
64                 return -EINVAL;
65
66         pc = tcf_hash_check(parm->index, a, bind, &pedit_hash_info);
67         if (!pc) {
68                 if (!parm->nkeys)
69                         return -EINVAL;
70                 pc = tcf_hash_create(parm->index, est, a, sizeof(*p), bind,
71                                      &pedit_idx_gen, &pedit_hash_info);
72                 if (IS_ERR(pc))
73                     return PTR_ERR(pc);
74                 p = to_pedit(pc);
75                 keys = kmalloc(ksize, GFP_KERNEL);
76                 if (keys == NULL) {
77                         kfree(pc);
78                         return -ENOMEM;
79                 }
80                 ret = ACT_P_CREATED;
81         } else {
82                 p = to_pedit(pc);
83                 if (!ovr) {
84                         tcf_hash_release(pc, bind, &pedit_hash_info);
85                         return -EEXIST;
86                 }
87                 if (p->tcfp_nkeys && p->tcfp_nkeys != parm->nkeys) {
88                         keys = kmalloc(ksize, GFP_KERNEL);
89                         if (keys == NULL)
90                                 return -ENOMEM;
91                 }
92         }
93
94         spin_lock_bh(&p->tcf_lock);
95         p->tcfp_flags = parm->flags;
96         p->tcf_action = parm->action;
97         if (keys) {
98                 kfree(p->tcfp_keys);
99                 p->tcfp_keys = keys;
100                 p->tcfp_nkeys = parm->nkeys;
101         }
102         memcpy(p->tcfp_keys, parm->keys, ksize);
103         spin_unlock_bh(&p->tcf_lock);
104         if (ret == ACT_P_CREATED)
105                 tcf_hash_insert(pc, &pedit_hash_info);
106         return ret;
107 }
108
109 static int tcf_pedit_cleanup(struct tc_action *a, int bind)
110 {
111         struct tcf_pedit *p = a->priv;
112
113         if (p) {
114                 struct tc_pedit_key *keys = p->tcfp_keys;
115                 if (tcf_hash_release(&p->common, bind, &pedit_hash_info)) {
116                         kfree(keys);
117                         return 1;
118                 }
119         }
120         return 0;
121 }
122
123 static int tcf_pedit(struct sk_buff *skb, struct tc_action *a,
124                      struct tcf_result *res)
125 {
126         struct tcf_pedit *p = a->priv;
127         int i, munged = 0;
128         unsigned int off;
129
130         if (skb_cloned(skb)) {
131                 if (pskb_expand_head(skb, 0, 0, GFP_ATOMIC)) {
132                         return p->tcf_action;
133                 }
134         }
135
136         off = skb_network_offset(skb);
137
138         spin_lock(&p->tcf_lock);
139
140         p->tcf_tm.lastuse = jiffies;
141
142         if (p->tcfp_nkeys > 0) {
143                 struct tc_pedit_key *tkey = p->tcfp_keys;
144
145                 for (i = p->tcfp_nkeys; i > 0; i--, tkey++) {
146                         u32 *ptr, _data;
147                         int offset = tkey->off;
148
149                         if (tkey->offmask) {
150                                 char *d, _d;
151
152                                 d = skb_header_pointer(skb, off + tkey->at, 1,
153                                                        &_d);
154                                 if (!d)
155                                         goto bad;
156                                 offset += (*d & tkey->offmask) >> tkey->shift;
157                         }
158
159                         if (offset % 4) {
160                                 pr_info("tc filter pedit"
161                                         " offset must be on 32 bit boundaries\n");
162                                 goto bad;
163                         }
164                         if (offset > 0 && offset > skb->len) {
165                                 pr_info("tc filter pedit"
166                                         " offset %d cant exceed pkt length %d\n",
167                                        offset, skb->len);
168                                 goto bad;
169                         }
170
171                         ptr = skb_header_pointer(skb, off + offset, 4, &_data);
172                         if (!ptr)
173                                 goto bad;
174                         /* just do it, baby */
175                         *ptr = ((*ptr & tkey->mask) ^ tkey->val);
176                         if (ptr == &_data)
177                                 skb_store_bits(skb, off + offset, ptr, 4);
178                         munged++;
179                 }
180
181                 if (munged)
182                         skb->tc_verd = SET_TC_MUNGED(skb->tc_verd);
183                 goto done;
184         } else
185                 WARN(1, "pedit BUG: index %d\n", p->tcf_index);
186
187 bad:
188         p->tcf_qstats.overlimits++;
189 done:
190         bstats_update(&p->tcf_bstats, skb);
191         spin_unlock(&p->tcf_lock);
192         return p->tcf_action;
193 }
194
195 static int tcf_pedit_dump(struct sk_buff *skb, struct tc_action *a,
196                           int bind, int ref)
197 {
198         unsigned char *b = skb_tail_pointer(skb);
199         struct tcf_pedit *p = a->priv;
200         struct tc_pedit *opt;
201         struct tcf_t t;
202         int s;
203
204         s = sizeof(*opt) + p->tcfp_nkeys * sizeof(struct tc_pedit_key);
205
206         /* netlink spinlocks held above us - must use ATOMIC */
207         opt = kzalloc(s, GFP_ATOMIC);
208         if (unlikely(!opt))
209                 return -ENOBUFS;
210
211         memcpy(opt->keys, p->tcfp_keys,
212                p->tcfp_nkeys * sizeof(struct tc_pedit_key));
213         opt->index = p->tcf_index;
214         opt->nkeys = p->tcfp_nkeys;
215         opt->flags = p->tcfp_flags;
216         opt->action = p->tcf_action;
217         opt->refcnt = p->tcf_refcnt - ref;
218         opt->bindcnt = p->tcf_bindcnt - bind;
219
220         NLA_PUT(skb, TCA_PEDIT_PARMS, s, opt);
221         t.install = jiffies_to_clock_t(jiffies - p->tcf_tm.install);
222         t.lastuse = jiffies_to_clock_t(jiffies - p->tcf_tm.lastuse);
223         t.expires = jiffies_to_clock_t(p->tcf_tm.expires);
224         NLA_PUT(skb, TCA_PEDIT_TM, sizeof(t), &t);
225         kfree(opt);
226         return skb->len;
227
228 nla_put_failure:
229         nlmsg_trim(skb, b);
230         kfree(opt);
231         return -1;
232 }
233
234 static struct tc_action_ops act_pedit_ops = {
235         .kind           =       "pedit",
236         .hinfo          =       &pedit_hash_info,
237         .type           =       TCA_ACT_PEDIT,
238         .capab          =       TCA_CAP_NONE,
239         .owner          =       THIS_MODULE,
240         .act            =       tcf_pedit,
241         .dump           =       tcf_pedit_dump,
242         .cleanup        =       tcf_pedit_cleanup,
243         .lookup         =       tcf_hash_search,
244         .init           =       tcf_pedit_init,
245         .walk           =       tcf_generic_walker
246 };
247
248 MODULE_AUTHOR("Jamal Hadi Salim(2002-4)");
249 MODULE_DESCRIPTION("Generic Packet Editor actions");
250 MODULE_LICENSE("GPL");
251
252 static int __init pedit_init_module(void)
253 {
254         return tcf_register_action(&act_pedit_ops);
255 }
256
257 static void __exit pedit_cleanup_module(void)
258 {
259         tcf_unregister_action(&act_pedit_ops);
260 }
261
262 module_init(pedit_init_module);
263 module_exit(pedit_cleanup_module);
264