Merge master.kernel.org:/pub/scm/linux/kernel/git/sfrench/cifs-2.6
[linux-2.6] / 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 <asm/uaccess.h>
13 #include <asm/system.h>
14 #include <asm/bitops.h>
15 #include <linux/types.h>
16 #include <linux/kernel.h>
17 #include <linux/sched.h>
18 #include <linux/string.h>
19 #include <linux/mm.h>
20 #include <linux/socket.h>
21 #include <linux/sockios.h>
22 #include <linux/in.h>
23 #include <linux/errno.h>
24 #include <linux/interrupt.h>
25 #include <linux/netdevice.h>
26 #include <linux/skbuff.h>
27 #include <linux/rtnetlink.h>
28 #include <linux/module.h>
29 #include <linux/init.h>
30 #include <linux/proc_fs.h>
31 #include <net/sock.h>
32 #include <net/pkt_sched.h>
33 #include <linux/tc_act/tc_pedit.h>
34 #include <net/tc_act/tc_pedit.h>
35
36 #define PEDIT_TAB_MASK  15
37 static struct tcf_common *tcf_pedit_ht[PEDIT_TAB_MASK + 1];
38 static u32 pedit_idx_gen;
39 static DEFINE_RWLOCK(pedit_lock);
40
41 static struct tcf_hashinfo pedit_hash_info = {
42         .htab   =       tcf_pedit_ht,
43         .hmask  =       PEDIT_TAB_MASK,
44         .lock   =       &pedit_lock,
45 };
46
47 static int tcf_pedit_init(struct rtattr *rta, struct rtattr *est,
48                           struct tc_action *a, int ovr, int bind)
49 {
50         struct rtattr *tb[TCA_PEDIT_MAX];
51         struct tc_pedit *parm;
52         int ret = 0;
53         struct tcf_pedit *p;
54         struct tcf_common *pc;
55         struct tc_pedit_key *keys = NULL;
56         int ksize;
57
58         if (rta == NULL || rtattr_parse_nested(tb, TCA_PEDIT_MAX, rta) < 0)
59                 return -EINVAL;
60
61         if (tb[TCA_PEDIT_PARMS - 1] == NULL ||
62             RTA_PAYLOAD(tb[TCA_PEDIT_PARMS-1]) < sizeof(*parm))
63                 return -EINVAL;
64         parm = RTA_DATA(tb[TCA_PEDIT_PARMS-1]);
65         ksize = parm->nkeys * sizeof(struct tc_pedit_key);
66         if (RTA_PAYLOAD(tb[TCA_PEDIT_PARMS-1]) < sizeof(*parm) + ksize)
67                 return -EINVAL;
68
69         pc = tcf_hash_check(parm->index, a, bind, &pedit_hash_info);
70         if (!pc) {
71                 if (!parm->nkeys)
72                         return -EINVAL;
73                 pc = tcf_hash_create(parm->index, est, a, sizeof(*p), bind,
74                                      &pedit_idx_gen, &pedit_hash_info);
75                 if (unlikely(!pc))
76                         return -ENOMEM;
77                 p = to_pedit(pc);
78                 keys = kmalloc(ksize, GFP_KERNEL);
79                 if (keys == NULL) {
80                         kfree(pc);
81                         return -ENOMEM;
82                 }
83                 ret = ACT_P_CREATED;
84         } else {
85                 p = to_pedit(pc);
86                 if (!ovr) {
87                         tcf_hash_release(pc, bind, &pedit_hash_info);
88                         return -EEXIST;
89                 }
90                 if (p->tcfp_nkeys && p->tcfp_nkeys != parm->nkeys) {
91                         keys = kmalloc(ksize, GFP_KERNEL);
92                         if (keys == NULL)
93                                 return -ENOMEM;
94                 }
95         }
96
97         spin_lock_bh(&p->tcf_lock);
98         p->tcfp_flags = parm->flags;
99         p->tcf_action = parm->action;
100         if (keys) {
101                 kfree(p->tcfp_keys);
102                 p->tcfp_keys = keys;
103                 p->tcfp_nkeys = parm->nkeys;
104         }
105         memcpy(p->tcfp_keys, parm->keys, ksize);
106         spin_unlock_bh(&p->tcf_lock);
107         if (ret == ACT_P_CREATED)
108                 tcf_hash_insert(pc, &pedit_hash_info);
109         return ret;
110 }
111
112 static int tcf_pedit_cleanup(struct tc_action *a, int bind)
113 {
114         struct tcf_pedit *p = a->priv;
115
116         if (p) {
117                 struct tc_pedit_key *keys = p->tcfp_keys;
118                 if (tcf_hash_release(&p->common, bind, &pedit_hash_info)) {
119                         kfree(keys);
120                         return 1;
121                 }
122         }
123         return 0;
124 }
125
126 static int tcf_pedit(struct sk_buff *skb, struct tc_action *a,
127                      struct tcf_result *res)
128 {
129         struct tcf_pedit *p = a->priv;
130         int i, munged = 0;
131         u8 *pptr;
132
133         if (!(skb->tc_verd & TC_OK2MUNGE)) {
134                 /* should we set skb->cloned? */
135                 if (pskb_expand_head(skb, 0, 0, GFP_ATOMIC)) {
136                         return p->tcf_action;
137                 }
138         }
139
140         pptr = skb->nh.raw;
141
142         spin_lock(&p->tcf_lock);
143
144         p->tcf_tm.lastuse = jiffies;
145
146         if (p->tcfp_nkeys > 0) {
147                 struct tc_pedit_key *tkey = p->tcfp_keys;
148
149                 for (i = p->tcfp_nkeys; i > 0; i--, tkey++) {
150                         u32 *ptr;
151                         int offset = tkey->off;
152
153                         if (tkey->offmask) {
154                                 if (skb->len > tkey->at) {
155                                          char *j = pptr + tkey->at;
156                                          offset += ((*j & tkey->offmask) >>
157                                                    tkey->shift);
158                                 } else {
159                                         goto bad;
160                                 }
161                         }
162
163                         if (offset % 4) {
164                                 printk("offset must be on 32 bit boundaries\n");
165                                 goto bad;
166                         }
167                         if (skb->len < 0 ||
168                             (offset > 0 && offset > skb->len)) {
169                                 printk("offset %d cant exceed pkt length %d\n",
170                                        offset, skb->len);
171                                 goto bad;
172                         }
173
174                         ptr = (u32 *)(pptr+offset);
175                         /* just do it, baby */
176                         *ptr = ((*ptr & tkey->mask) ^ tkey->val);
177                         munged++;
178                 }
179
180                 if (munged)
181                         skb->tc_verd = SET_TC_MUNGED(skb->tc_verd);
182                 goto done;
183         } else {
184                 printk("pedit BUG: index %d\n", p->tcf_index);
185         }
186
187 bad:
188         p->tcf_qstats.overlimits++;
189 done:
190         p->tcf_bstats.bytes += skb->len;
191         p->tcf_bstats.packets++;
192         spin_unlock(&p->tcf_lock);
193         return p->tcf_action;
194 }
195
196 static int tcf_pedit_dump(struct sk_buff *skb, struct tc_action *a,
197                           int bind, int ref)
198 {
199         unsigned char *b = skb->tail;
200         struct tcf_pedit *p = a->priv;
201         struct tc_pedit *opt;
202         struct tcf_t t;
203         int s;
204
205         s = sizeof(*opt) + p->tcfp_nkeys * sizeof(struct tc_pedit_key);
206
207         /* netlink spinlocks held above us - must use ATOMIC */
208         opt = kzalloc(s, GFP_ATOMIC);
209         if (unlikely(!opt))
210                 return -ENOBUFS;
211
212         memcpy(opt->keys, p->tcfp_keys,
213                p->tcfp_nkeys * sizeof(struct tc_pedit_key));
214         opt->index = p->tcf_index;
215         opt->nkeys = p->tcfp_nkeys;
216         opt->flags = p->tcfp_flags;
217         opt->action = p->tcf_action;
218         opt->refcnt = p->tcf_refcnt - ref;
219         opt->bindcnt = p->tcf_bindcnt - bind;
220
221         RTA_PUT(skb, TCA_PEDIT_PARMS, s, opt);
222         t.install = jiffies_to_clock_t(jiffies - p->tcf_tm.install);
223         t.lastuse = jiffies_to_clock_t(jiffies - p->tcf_tm.lastuse);
224         t.expires = jiffies_to_clock_t(p->tcf_tm.expires);
225         RTA_PUT(skb, TCA_PEDIT_TM, sizeof(t), &t);
226         kfree(opt);
227         return skb->len;
228
229 rtattr_failure:
230         skb_trim(skb, b - skb->data);
231         kfree(opt);
232         return -1;
233 }
234
235 static struct tc_action_ops act_pedit_ops = {
236         .kind           =       "pedit",
237         .hinfo          =       &pedit_hash_info,
238         .type           =       TCA_ACT_PEDIT,
239         .capab          =       TCA_CAP_NONE,
240         .owner          =       THIS_MODULE,
241         .act            =       tcf_pedit,
242         .dump           =       tcf_pedit_dump,
243         .cleanup        =       tcf_pedit_cleanup,
244         .lookup         =       tcf_hash_search,
245         .init           =       tcf_pedit_init,
246         .walk           =       tcf_generic_walker
247 };
248
249 MODULE_AUTHOR("Jamal Hadi Salim(2002-4)");
250 MODULE_DESCRIPTION("Generic Packet Editor actions");
251 MODULE_LICENSE("GPL");
252
253 static int __init pedit_init_module(void)
254 {
255         return tcf_register_action(&act_pedit_ops);
256 }
257
258 static void __exit pedit_cleanup_module(void)
259 {
260         tcf_unregister_action(&act_pedit_ops);
261 }
262
263 module_init(pedit_init_module);
264 module_exit(pedit_cleanup_module);
265