Merge branch 'for-linus' of git://git.selinuxproject.org/~jmorris/linux-security
[pandora-kernel.git] / net / sched / act_simple.c
1 /*
2  * net/sched/simp.c     Simple example of an action
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 (2005-8)
10  *
11  */
12
13 #include <linux/module.h>
14 #include <linux/slab.h>
15 #include <linux/init.h>
16 #include <linux/kernel.h>
17 #include <linux/skbuff.h>
18 #include <linux/rtnetlink.h>
19 #include <net/netlink.h>
20 #include <net/pkt_sched.h>
21
22 #define TCA_ACT_SIMP 22
23
24 #include <linux/tc_act/tc_defact.h>
25 #include <net/tc_act/tc_defact.h>
26
27 #define SIMP_TAB_MASK     7
28 static struct tcf_common *tcf_simp_ht[SIMP_TAB_MASK + 1];
29 static u32 simp_idx_gen;
30 static DEFINE_RWLOCK(simp_lock);
31
32 static struct tcf_hashinfo simp_hash_info = {
33         .htab   =       tcf_simp_ht,
34         .hmask  =       SIMP_TAB_MASK,
35         .lock   =       &simp_lock,
36 };
37
38 #define SIMP_MAX_DATA   32
39 static int tcf_simp(struct sk_buff *skb, const struct tc_action *a,
40                     struct tcf_result *res)
41 {
42         struct tcf_defact *d = a->priv;
43
44         spin_lock(&d->tcf_lock);
45         d->tcf_tm.lastuse = jiffies;
46         bstats_update(&d->tcf_bstats, skb);
47
48         /* print policy string followed by _ then packet count
49          * Example if this was the 3rd packet and the string was "hello"
50          * then it would look like "hello_3" (without quotes)
51          */
52         pr_info("simple: %s_%d\n",
53                (char *)d->tcfd_defdata, d->tcf_bstats.packets);
54         spin_unlock(&d->tcf_lock);
55         return d->tcf_action;
56 }
57
58 static int tcf_simp_release(struct tcf_defact *d, int bind)
59 {
60         int ret = 0;
61         if (d) {
62                 if (bind)
63                         d->tcf_bindcnt--;
64                 d->tcf_refcnt--;
65                 if (d->tcf_bindcnt <= 0 && d->tcf_refcnt <= 0) {
66                         kfree(d->tcfd_defdata);
67                         tcf_hash_destroy(&d->common, &simp_hash_info);
68                         ret = 1;
69                 }
70         }
71         return ret;
72 }
73
74 static int alloc_defdata(struct tcf_defact *d, char *defdata)
75 {
76         d->tcfd_defdata = kzalloc(SIMP_MAX_DATA, GFP_KERNEL);
77         if (unlikely(!d->tcfd_defdata))
78                 return -ENOMEM;
79         strlcpy(d->tcfd_defdata, defdata, SIMP_MAX_DATA);
80         return 0;
81 }
82
83 static void reset_policy(struct tcf_defact *d, char *defdata,
84                          struct tc_defact *p)
85 {
86         spin_lock_bh(&d->tcf_lock);
87         d->tcf_action = p->action;
88         memset(d->tcfd_defdata, 0, SIMP_MAX_DATA);
89         strlcpy(d->tcfd_defdata, defdata, SIMP_MAX_DATA);
90         spin_unlock_bh(&d->tcf_lock);
91 }
92
93 static const struct nla_policy simple_policy[TCA_DEF_MAX + 1] = {
94         [TCA_DEF_PARMS] = { .len = sizeof(struct tc_defact) },
95         [TCA_DEF_DATA]  = { .type = NLA_STRING, .len = SIMP_MAX_DATA },
96 };
97
98 static int tcf_simp_init(struct nlattr *nla, struct nlattr *est,
99                          struct tc_action *a, int ovr, int bind)
100 {
101         struct nlattr *tb[TCA_DEF_MAX + 1];
102         struct tc_defact *parm;
103         struct tcf_defact *d;
104         struct tcf_common *pc;
105         char *defdata;
106         int ret = 0, err;
107
108         if (nla == NULL)
109                 return -EINVAL;
110
111         err = nla_parse_nested(tb, TCA_DEF_MAX, nla, simple_policy);
112         if (err < 0)
113                 return err;
114
115         if (tb[TCA_DEF_PARMS] == NULL)
116                 return -EINVAL;
117
118         if (tb[TCA_DEF_DATA] == NULL)
119                 return -EINVAL;
120
121         parm = nla_data(tb[TCA_DEF_PARMS]);
122         defdata = nla_data(tb[TCA_DEF_DATA]);
123
124         pc = tcf_hash_check(parm->index, a, bind, &simp_hash_info);
125         if (!pc) {
126                 pc = tcf_hash_create(parm->index, est, a, sizeof(*d), bind,
127                                      &simp_idx_gen, &simp_hash_info);
128                 if (IS_ERR(pc))
129                         return PTR_ERR(pc);
130
131                 d = to_defact(pc);
132                 ret = alloc_defdata(d, defdata);
133                 if (ret < 0) {
134                         kfree(pc);
135                         return ret;
136                 }
137                 d->tcf_action = parm->action;
138                 ret = ACT_P_CREATED;
139         } else {
140                 d = to_defact(pc);
141                 if (!ovr) {
142                         tcf_simp_release(d, bind);
143                         return -EEXIST;
144                 }
145                 reset_policy(d, defdata, parm);
146         }
147
148         if (ret == ACT_P_CREATED)
149                 tcf_hash_insert(pc, &simp_hash_info);
150         return ret;
151 }
152
153 static int tcf_simp_cleanup(struct tc_action *a, int bind)
154 {
155         struct tcf_defact *d = a->priv;
156
157         if (d)
158                 return tcf_simp_release(d, bind);
159         return 0;
160 }
161
162 static int tcf_simp_dump(struct sk_buff *skb, struct tc_action *a,
163                          int bind, int ref)
164 {
165         unsigned char *b = skb_tail_pointer(skb);
166         struct tcf_defact *d = a->priv;
167         struct tc_defact opt = {
168                 .index   = d->tcf_index,
169                 .refcnt  = d->tcf_refcnt - ref,
170                 .bindcnt = d->tcf_bindcnt - bind,
171                 .action  = d->tcf_action,
172         };
173         struct tcf_t t;
174
175         NLA_PUT(skb, TCA_DEF_PARMS, sizeof(opt), &opt);
176         NLA_PUT_STRING(skb, TCA_DEF_DATA, d->tcfd_defdata);
177         t.install = jiffies_to_clock_t(jiffies - d->tcf_tm.install);
178         t.lastuse = jiffies_to_clock_t(jiffies - d->tcf_tm.lastuse);
179         t.expires = jiffies_to_clock_t(d->tcf_tm.expires);
180         NLA_PUT(skb, TCA_DEF_TM, sizeof(t), &t);
181         return skb->len;
182
183 nla_put_failure:
184         nlmsg_trim(skb, b);
185         return -1;
186 }
187
188 static struct tc_action_ops act_simp_ops = {
189         .kind           =       "simple",
190         .hinfo          =       &simp_hash_info,
191         .type           =       TCA_ACT_SIMP,
192         .capab          =       TCA_CAP_NONE,
193         .owner          =       THIS_MODULE,
194         .act            =       tcf_simp,
195         .dump           =       tcf_simp_dump,
196         .cleanup        =       tcf_simp_cleanup,
197         .init           =       tcf_simp_init,
198         .walk           =       tcf_generic_walker,
199 };
200
201 MODULE_AUTHOR("Jamal Hadi Salim(2005)");
202 MODULE_DESCRIPTION("Simple example action");
203 MODULE_LICENSE("GPL");
204
205 static int __init simp_init_module(void)
206 {
207         int ret = tcf_register_action(&act_simp_ops);
208         if (!ret)
209                 pr_info("Simple TC action Loaded\n");
210         return ret;
211 }
212
213 static void __exit simp_cleanup_module(void)
214 {
215         tcf_unregister_action(&act_simp_ops);
216 }
217
218 module_init(simp_init_module);
219 module_exit(simp_cleanup_module);