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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 net *net, struct nlattr *nla,
66 struct nlattr *est, struct tc_action *a, int ovr,
67 int bind)
68{
69 struct nlattr *tb[TCA_MIRRED_MAX + 1];
70 struct tc_mirred *parm;
71 struct tcf_mirred *m;
72 struct tcf_common *pc;
73 struct net_device *dev;
74 int ret, ok_push = 0;
75
76 if (nla == NULL)
77 return -EINVAL;
78 ret = nla_parse_nested(tb, TCA_MIRRED_MAX, nla, mirred_policy);
79 if (ret < 0)
80 return ret;
81 if (tb[TCA_MIRRED_PARMS] == NULL)
82 return -EINVAL;
83 parm = nla_data(tb[TCA_MIRRED_PARMS]);
84 switch (parm->eaction) {
85 case TCA_EGRESS_MIRROR:
86 case TCA_EGRESS_REDIR:
87 break;
88 default:
89 return -EINVAL;
90 }
91 if (parm->ifindex) {
92 dev = __dev_get_by_index(net, parm->ifindex);
93 if (dev == NULL)
94 return -ENODEV;
95 switch (dev->type) {
96 case ARPHRD_TUNNEL:
97 case ARPHRD_TUNNEL6:
98 case ARPHRD_SIT:
99 case ARPHRD_IPGRE:
100 case ARPHRD_VOID:
101 case ARPHRD_NONE:
102 ok_push = 0;
103 break;
104 default:
105 ok_push = 1;
106 break;
107 }
108 } else {
109 dev = NULL;
110 }
111
112 pc = tcf_hash_check(parm->index, a, bind, &mirred_hash_info);
113 if (!pc) {
114 if (dev == NULL)
115 return -EINVAL;
116 pc = tcf_hash_create(parm->index, est, a, sizeof(*m), bind,
117 &mirred_idx_gen, &mirred_hash_info);
118 if (IS_ERR(pc))
119 return PTR_ERR(pc);
120 ret = ACT_P_CREATED;
121 } else {
122 if (!ovr) {
123 tcf_mirred_release(to_mirred(pc), bind);
124 return -EEXIST;
125 }
126 }
127 m = to_mirred(pc);
128
129 spin_lock_bh(&m->tcf_lock);
130 m->tcf_action = parm->action;
131 m->tcfm_eaction = parm->eaction;
132 if (dev != NULL) {
133 m->tcfm_ifindex = parm->ifindex;
134 if (ret != ACT_P_CREATED)
135 dev_put(m->tcfm_dev);
136 dev_hold(dev);
137 m->tcfm_dev = dev;
138 m->tcfm_ok_push = ok_push;
139 }
140 spin_unlock_bh(&m->tcf_lock);
141 if (ret == ACT_P_CREATED) {
142 list_add(&m->tcfm_list, &mirred_list);
143 tcf_hash_insert(pc, &mirred_hash_info);
144 }
145
146 return ret;
147}
148
149static int tcf_mirred_cleanup(struct tc_action *a, int bind)
150{
151 struct tcf_mirred *m = a->priv;
152
153 if (m)
154 return tcf_mirred_release(m, bind);
155 return 0;
156}
157
158static int tcf_mirred(struct sk_buff *skb, const struct tc_action *a,
159 struct tcf_result *res)
160{
161 struct tcf_mirred *m = a->priv;
162 struct net_device *dev;
163 struct sk_buff *skb2;
164 u32 at;
165 int retval, err = 1;
166
167 spin_lock(&m->tcf_lock);
168 m->tcf_tm.lastuse = jiffies;
169 bstats_update(&m->tcf_bstats, skb);
170
171 dev = m->tcfm_dev;
172 if (!dev) {
173 printk_once(KERN_NOTICE "tc mirred: target device is gone\n");
174 goto out;
175 }
176
177 if (!(dev->flags & IFF_UP)) {
178 net_notice_ratelimited("tc mirred to Houston: device %s is down\n",
179 dev->name);
180 goto out;
181 }
182
183 at = G_TC_AT(skb->tc_verd);
184 skb2 = skb_act_clone(skb, GFP_ATOMIC, m->tcf_action);
185 if (skb2 == NULL)
186 goto out;
187
188 if (!(at & AT_EGRESS)) {
189 if (m->tcfm_ok_push)
190 skb_push(skb2, skb2->dev->hard_header_len);
191 }
192
193
194 if (m->tcfm_eaction != TCA_EGRESS_MIRROR)
195 skb2->tc_verd = SET_TC_FROM(skb2->tc_verd, at);
196
197 skb2->skb_iif = skb->dev->ifindex;
198 skb2->dev = dev;
199 err = dev_queue_xmit(skb2);
200
201out:
202 if (err) {
203 m->tcf_qstats.overlimits++;
204 if (m->tcfm_eaction != TCA_EGRESS_MIRROR)
205 retval = TC_ACT_SHOT;
206 else
207 retval = m->tcf_action;
208 } else
209 retval = m->tcf_action;
210 spin_unlock(&m->tcf_lock);
211
212 return retval;
213}
214
215static int tcf_mirred_dump(struct sk_buff *skb, struct tc_action *a, int bind, int ref)
216{
217 unsigned char *b = skb_tail_pointer(skb);
218 struct tcf_mirred *m = a->priv;
219 struct tc_mirred opt = {
220 .index = m->tcf_index,
221 .action = m->tcf_action,
222 .refcnt = m->tcf_refcnt - ref,
223 .bindcnt = m->tcf_bindcnt - bind,
224 .eaction = m->tcfm_eaction,
225 .ifindex = m->tcfm_ifindex,
226 };
227 struct tcf_t t;
228
229 if (nla_put(skb, TCA_MIRRED_PARMS, sizeof(opt), &opt))
230 goto nla_put_failure;
231 t.install = jiffies_to_clock_t(jiffies - m->tcf_tm.install);
232 t.lastuse = jiffies_to_clock_t(jiffies - m->tcf_tm.lastuse);
233 t.expires = jiffies_to_clock_t(m->tcf_tm.expires);
234 if (nla_put(skb, TCA_MIRRED_TM, sizeof(t), &t))
235 goto nla_put_failure;
236 return skb->len;
237
238nla_put_failure:
239 nlmsg_trim(skb, b);
240 return -1;
241}
242
243static int mirred_device_event(struct notifier_block *unused,
244 unsigned long event, void *ptr)
245{
246 struct net_device *dev = ptr;
247 struct tcf_mirred *m;
248
249 if (event == NETDEV_UNREGISTER)
250 list_for_each_entry(m, &mirred_list, tcfm_list) {
251 if (m->tcfm_dev == dev) {
252 dev_put(dev);
253 m->tcfm_dev = NULL;
254 }
255 }
256
257 return NOTIFY_DONE;
258}
259
260static struct notifier_block mirred_device_notifier = {
261 .notifier_call = mirred_device_event,
262};
263
264
265static struct tc_action_ops act_mirred_ops = {
266 .kind = "mirred",
267 .hinfo = &mirred_hash_info,
268 .type = TCA_ACT_MIRRED,
269 .capab = TCA_CAP_NONE,
270 .owner = THIS_MODULE,
271 .act = tcf_mirred,
272 .dump = tcf_mirred_dump,
273 .cleanup = tcf_mirred_cleanup,
274 .lookup = tcf_hash_search,
275 .init = tcf_mirred_init,
276 .walk = tcf_generic_walker
277};
278
279MODULE_AUTHOR("Jamal Hadi Salim(2002)");
280MODULE_DESCRIPTION("Device Mirror/redirect actions");
281MODULE_LICENSE("GPL");
282
283static int __init mirred_init_module(void)
284{
285 int err = register_netdevice_notifier(&mirred_device_notifier);
286 if (err)
287 return err;
288
289 pr_info("Mirror/redirect action on\n");
290 return tcf_register_action(&act_mirred_ops);
291}
292
293static void __exit mirred_cleanup_module(void)
294{
295 unregister_netdevice_notifier(&mirred_device_notifier);
296 tcf_unregister_action(&act_mirred_ops);
297}
298
299module_init(mirred_init_module);
300module_exit(mirred_cleanup_module);
301
