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15#include <linux/types.h>
16#include <linux/kernel.h>
17#include <linux/string.h>
18#include <linux/errno.h>
19#include <linux/skbuff.h>
20#include <linux/rtnetlink.h>
21#include <linux/module.h>
22#include <linux/init.h>
23#include <linux/gfp.h>
24#include <net/net_namespace.h>
25#include <net/netlink.h>
26#include <net/pkt_sched.h>
27#include <linux/tc_act/tc_mirred.h>
28#include <net/tc_act/tc_mirred.h>
29
30#include <linux/if_arp.h>
31
32#define MIRRED_TAB_MASK 7
33static struct tcf_common *tcf_mirred_ht[MIRRED_TAB_MASK + 1];
34static u32 mirred_idx_gen;
35static DEFINE_RWLOCK(mirred_lock);
36static LIST_HEAD(mirred_list);
37
38static struct tcf_hashinfo mirred_hash_info = {
39 .htab = tcf_mirred_ht,
40 .hmask = MIRRED_TAB_MASK,
41 .lock = &mirred_lock,
42};
43
44static int tcf_mirred_release(struct tcf_mirred *m, int bind)
45{
46 if (m) {
47 if (bind)
48 m->tcf_bindcnt--;
49 m->tcf_refcnt--;
50 if (!m->tcf_bindcnt && m->tcf_refcnt <= 0) {
51 list_del(&m->tcfm_list);
52 if (m->tcfm_dev)
53 dev_put(m->tcfm_dev);
54 tcf_hash_destroy(&m->common, &mirred_hash_info);
55 return 1;
56 }
57 }
58 return 0;
59}
60
61static const struct nla_policy mirred_policy[TCA_MIRRED_MAX + 1] = {
62 [TCA_MIRRED_PARMS] = { .len = sizeof(struct tc_mirred) },
63};
64
65static int tcf_mirred_init(struct nlattr *nla, struct nlattr *est,
66 struct tc_action *a, int ovr, int bind)
67{
68 struct nlattr *tb[TCA_MIRRED_MAX + 1];
69 struct tc_mirred *parm;
70 struct tcf_mirred *m;
71 struct tcf_common *pc;
72 struct net_device *dev;
73 int ret, ok_push = 0;
74
75 if (nla == NULL)
76 return -EINVAL;
77 ret = nla_parse_nested(tb, TCA_MIRRED_MAX, nla, mirred_policy);
78 if (ret < 0)
79 return ret;
80 if (tb[TCA_MIRRED_PARMS] == NULL)
81 return -EINVAL;
82 parm = nla_data(tb[TCA_MIRRED_PARMS]);
83 switch (parm->eaction) {
84 case TCA_EGRESS_MIRROR:
85 case TCA_EGRESS_REDIR:
86 break;
87 default:
88 return -EINVAL;
89 }
90 if (parm->ifindex) {
91 dev = __dev_get_by_index(&init_net, parm->ifindex);
92 if (dev == NULL)
93 return -ENODEV;
94 switch (dev->type) {
95 case ARPHRD_TUNNEL:
96 case ARPHRD_TUNNEL6:
97 case ARPHRD_SIT:
98 case ARPHRD_IPGRE:
99 case ARPHRD_VOID:
100 case ARPHRD_NONE:
101 ok_push = 0;
102 break;
103 default:
104 ok_push = 1;
105 break;
106 }
107 } else {
108 dev = NULL;
109 }
110
111 pc = tcf_hash_check(parm->index, a, bind, &mirred_hash_info);
112 if (!pc) {
113 if (dev == NULL)
114 return -EINVAL;
115 pc = tcf_hash_create(parm->index, est, a, sizeof(*m), bind,
116 &mirred_idx_gen, &mirred_hash_info);
117 if (IS_ERR(pc))
118 return PTR_ERR(pc);
119 ret = ACT_P_CREATED;
120 } else {
121 if (!ovr) {
122 tcf_mirred_release(to_mirred(pc), bind);
123 return -EEXIST;
124 }
125 }
126 m = to_mirred(pc);
127
128 spin_lock_bh(&m->tcf_lock);
129 m->tcf_action = parm->action;
130 m->tcfm_eaction = parm->eaction;
131 if (dev != NULL) {
132 m->tcfm_ifindex = parm->ifindex;
133 if (ret != ACT_P_CREATED)
134 dev_put(m->tcfm_dev);
135 dev_hold(dev);
136 m->tcfm_dev = dev;
137 m->tcfm_ok_push = ok_push;
138 }
139 spin_unlock_bh(&m->tcf_lock);
140 if (ret == ACT_P_CREATED) {
141 list_add(&m->tcfm_list, &mirred_list);
142 tcf_hash_insert(pc, &mirred_hash_info);
143 }
144
145 return ret;
146}
147
148static int tcf_mirred_cleanup(struct tc_action *a, int bind)
149{
150 struct tcf_mirred *m = a->priv;
151
152 if (m)
153 return tcf_mirred_release(m, bind);
154 return 0;
155}
156
157static int tcf_mirred(struct sk_buff *skb, const struct tc_action *a,
158 struct tcf_result *res)
159{
160 struct tcf_mirred *m = a->priv;
161 struct net_device *dev;
162 struct sk_buff *skb2;
163 u32 at;
164 int retval, err = 1;
165
166 spin_lock(&m->tcf_lock);
167 m->tcf_tm.lastuse = jiffies;
168 bstats_update(&m->tcf_bstats, skb);
169
170 dev = m->tcfm_dev;
171 if (!dev) {
172 printk_once(KERN_NOTICE "tc mirred: target device is gone\n");
173 goto out;
174 }
175
176 if (!(dev->flags & IFF_UP)) {
177 net_notice_ratelimited("tc mirred to Houston: device %s is down\n",
178 dev->name);
179 goto out;
180 }
181
182 at = G_TC_AT(skb->tc_verd);
183 skb2 = skb_act_clone(skb, GFP_ATOMIC, m->tcf_action);
184 if (skb2 == NULL)
185 goto out;
186
187 if (!(at & AT_EGRESS)) {
188 if (m->tcfm_ok_push)
189 skb_push(skb2, skb2->dev->hard_header_len);
190 }
191
192
193 if (m->tcfm_eaction != TCA_EGRESS_MIRROR)
194 skb2->tc_verd = SET_TC_FROM(skb2->tc_verd, at);
195
196 skb2->skb_iif = skb->dev->ifindex;
197 skb2->dev = dev;
198 err = dev_queue_xmit(skb2);
199
200out:
201 if (err) {
202 m->tcf_qstats.overlimits++;
203 if (m->tcfm_eaction != TCA_EGRESS_MIRROR)
204 retval = TC_ACT_SHOT;
205 else
206 retval = m->tcf_action;
207 } else
208 retval = m->tcf_action;
209 spin_unlock(&m->tcf_lock);
210
211 return retval;
212}
213
214static int tcf_mirred_dump(struct sk_buff *skb, struct tc_action *a, int bind, int ref)
215{
216 unsigned char *b = skb_tail_pointer(skb);
217 struct tcf_mirred *m = a->priv;
218 struct tc_mirred opt = {
219 .index = m->tcf_index,
220 .action = m->tcf_action,
221 .refcnt = m->tcf_refcnt - ref,
222 .bindcnt = m->tcf_bindcnt - bind,
223 .eaction = m->tcfm_eaction,
224 .ifindex = m->tcfm_ifindex,
225 };
226 struct tcf_t t;
227
228 if (nla_put(skb, TCA_MIRRED_PARMS, sizeof(opt), &opt))
229 goto nla_put_failure;
230 t.install = jiffies_to_clock_t(jiffies - m->tcf_tm.install);
231 t.lastuse = jiffies_to_clock_t(jiffies - m->tcf_tm.lastuse);
232 t.expires = jiffies_to_clock_t(m->tcf_tm.expires);
233 if (nla_put(skb, TCA_MIRRED_TM, sizeof(t), &t))
234 goto nla_put_failure;
235 return skb->len;
236
237nla_put_failure:
238 nlmsg_trim(skb, b);
239 return -1;
240}
241
242static int mirred_device_event(struct notifier_block *unused,
243 unsigned long event, void *ptr)
244{
245 struct net_device *dev = ptr;
246 struct tcf_mirred *m;
247
248 if (event == NETDEV_UNREGISTER)
249 list_for_each_entry(m, &mirred_list, tcfm_list) {
250 if (m->tcfm_dev == dev) {
251 dev_put(dev);
252 m->tcfm_dev = NULL;
253 }
254 }
255
256 return NOTIFY_DONE;
257}
258
259static struct notifier_block mirred_device_notifier = {
260 .notifier_call = mirred_device_event,
261};
262
263
264static struct tc_action_ops act_mirred_ops = {
265 .kind = "mirred",
266 .hinfo = &mirred_hash_info,
267 .type = TCA_ACT_MIRRED,
268 .capab = TCA_CAP_NONE,
269 .owner = THIS_MODULE,
270 .act = tcf_mirred,
271 .dump = tcf_mirred_dump,
272 .cleanup = tcf_mirred_cleanup,
273 .lookup = tcf_hash_search,
274 .init = tcf_mirred_init,
275 .walk = tcf_generic_walker
276};
277
278MODULE_AUTHOR("Jamal Hadi Salim(2002)");
279MODULE_DESCRIPTION("Device Mirror/redirect actions");
280MODULE_LICENSE("GPL");
281
282static int __init mirred_init_module(void)
283{
284 int err = register_netdevice_notifier(&mirred_device_notifier);
285 if (err)
286 return err;
287
288 pr_info("Mirror/redirect action on\n");
289 return tcf_register_action(&act_mirred_ops);
290}
291
292static void __exit mirred_cleanup_module(void)
293{
294 unregister_netdevice_notifier(&mirred_device_notifier);
295 tcf_unregister_action(&act_mirred_ops);
296}
297
298module_init(mirred_init_module);
299module_exit(mirred_cleanup_module);
300
