tjh.dev
Linux kernel mirror (for testing)
git.kernel.org/pub/scm/linux/kernel/git/torvalds/linux.git
kernel
os
linux
1/*
2 * net/sched/mirred.c packet mirroring and redirect actions
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 * TODO: Add ingress support (and socket redirect support)
12 *
13 */
14
15#include <asm/uaccess.h>
16#include <asm/system.h>
17#include <asm/bitops.h>
18#include <linux/config.h>
19#include <linux/types.h>
20#include <linux/kernel.h>
21#include <linux/sched.h>
22#include <linux/string.h>
23#include <linux/mm.h>
24#include <linux/socket.h>
25#include <linux/sockios.h>
26#include <linux/in.h>
27#include <linux/errno.h>
28#include <linux/interrupt.h>
29#include <linux/netdevice.h>
30#include <linux/skbuff.h>
31#include <linux/rtnetlink.h>
32#include <linux/module.h>
33#include <linux/init.h>
34#include <linux/proc_fs.h>
35#include <net/sock.h>
36#include <net/pkt_sched.h>
37#include <linux/tc_act/tc_mirred.h>
38#include <net/tc_act/tc_mirred.h>
39
40#include <linux/etherdevice.h>
41#include <linux/if_arp.h>
42
43
44/* use generic hash table */
45#define MY_TAB_SIZE 8
46#define MY_TAB_MASK (MY_TAB_SIZE - 1)
47static u32 idx_gen;
48static struct tcf_mirred *tcf_mirred_ht[MY_TAB_SIZE];
49static DEFINE_RWLOCK(mirred_lock);
50
51/* ovewrride the defaults */
52#define tcf_st tcf_mirred
53#define tc_st tc_mirred
54#define tcf_t_lock mirred_lock
55#define tcf_ht tcf_mirred_ht
56
57#define CONFIG_NET_ACT_INIT 1
58#include <net/pkt_act.h>
59
60static inline int
61tcf_mirred_release(struct tcf_mirred *p, int bind)
62{
63 if (p) {
64 if (bind)
65 p->bindcnt--;
66 p->refcnt--;
67 if(!p->bindcnt && p->refcnt <= 0) {
68 dev_put(p->dev);
69 tcf_hash_destroy(p);
70 return 1;
71 }
72 }
73 return 0;
74}
75
76static int
77tcf_mirred_init(struct rtattr *rta, struct rtattr *est, struct tc_action *a,
78 int ovr, int bind)
79{
80 struct rtattr *tb[TCA_MIRRED_MAX];
81 struct tc_mirred *parm;
82 struct tcf_mirred *p;
83 struct net_device *dev = NULL;
84 int ret = 0;
85 int ok_push = 0;
86
87 if (rta == NULL || rtattr_parse_nested(tb, TCA_MIRRED_MAX, rta) < 0)
88 return -EINVAL;
89
90 if (tb[TCA_MIRRED_PARMS-1] == NULL ||
91 RTA_PAYLOAD(tb[TCA_MIRRED_PARMS-1]) < sizeof(*parm))
92 return -EINVAL;
93 parm = RTA_DATA(tb[TCA_MIRRED_PARMS-1]);
94
95 if (parm->ifindex) {
96 dev = __dev_get_by_index(parm->ifindex);
97 if (dev == NULL)
98 return -ENODEV;
99 switch (dev->type) {
100 case ARPHRD_TUNNEL:
101 case ARPHRD_TUNNEL6:
102 case ARPHRD_SIT:
103 case ARPHRD_IPGRE:
104 case ARPHRD_VOID:
105 case ARPHRD_NONE:
106 ok_push = 0;
107 break;
108 default:
109 ok_push = 1;
110 break;
111 }
112 }
113
114 p = tcf_hash_check(parm->index, a, ovr, bind);
115 if (p == NULL) {
116 if (!parm->ifindex)
117 return -EINVAL;
118 p = tcf_hash_create(parm->index, est, a, sizeof(*p), ovr, bind);
119 if (p == NULL)
120 return -ENOMEM;
121 ret = ACT_P_CREATED;
122 } else {
123 if (!ovr) {
124 tcf_mirred_release(p, bind);
125 return -EEXIST;
126 }
127 }
128
129 spin_lock_bh(&p->lock);
130 p->action = parm->action;
131 p->eaction = parm->eaction;
132 if (parm->ifindex) {
133 p->ifindex = parm->ifindex;
134 if (ret != ACT_P_CREATED)
135 dev_put(p->dev);
136 p->dev = dev;
137 dev_hold(dev);
138 p->ok_push = ok_push;
139 }
140 spin_unlock_bh(&p->lock);
141 if (ret == ACT_P_CREATED)
142 tcf_hash_insert(p);
143
144 DPRINTK("tcf_mirred_init index %d action %d eaction %d device %s "
145 "ifindex %d\n", parm->index, parm->action, parm->eaction,
146 dev->name, parm->ifindex);
147 return ret;
148}
149
150static int
151tcf_mirred_cleanup(struct tc_action *a, int bind)
152{
153 struct tcf_mirred *p = PRIV(a, mirred);
154
155 if (p != NULL)
156 return tcf_mirred_release(p, bind);
157 return 0;
158}
159
160static int
161tcf_mirred(struct sk_buff **pskb, struct tc_action *a, struct tcf_result *res)
162{
163 struct tcf_mirred *p = PRIV(a, mirred);
164 struct net_device *dev;
165 struct sk_buff *skb2 = NULL;
166 struct sk_buff *skb = *pskb;
167 u32 at = G_TC_AT(skb->tc_verd);
168
169 spin_lock(&p->lock);
170
171 dev = p->dev;
172 p->tm.lastuse = jiffies;
173
174 if (!(dev->flags&IFF_UP) ) {
175 if (net_ratelimit())
176 printk("mirred to Houston: device %s is gone!\n",
177 dev->name);
178bad_mirred:
179 if (skb2 != NULL)
180 kfree_skb(skb2);
181 p->qstats.overlimits++;
182 p->bstats.bytes += skb->len;
183 p->bstats.packets++;
184 spin_unlock(&p->lock);
185 /* should we be asking for packet to be dropped?
186 * may make sense for redirect case only
187 */
188 return TC_ACT_SHOT;
189 }
190
191 skb2 = skb_clone(skb, GFP_ATOMIC);
192 if (skb2 == NULL)
193 goto bad_mirred;
194 if (p->eaction != TCA_EGRESS_MIRROR && p->eaction != TCA_EGRESS_REDIR) {
195 if (net_ratelimit())
196 printk("tcf_mirred unknown action %d\n", p->eaction);
197 goto bad_mirred;
198 }
199
200 p->bstats.bytes += skb2->len;
201 p->bstats.packets++;
202 if (!(at & AT_EGRESS))
203 if (p->ok_push)
204 skb_push(skb2, skb2->dev->hard_header_len);
205
206 /* mirror is always swallowed */
207 if (p->eaction != TCA_EGRESS_MIRROR)
208 skb2->tc_verd = SET_TC_FROM(skb2->tc_verd, at);
209
210 skb2->dev = dev;
211 skb2->input_dev = skb->dev;
212 dev_queue_xmit(skb2);
213 spin_unlock(&p->lock);
214 return p->action;
215}
216
217static int
218tcf_mirred_dump(struct sk_buff *skb, struct tc_action *a, int bind, int ref)
219{
220 unsigned char *b = skb->tail;
221 struct tc_mirred opt;
222 struct tcf_mirred *p = PRIV(a, mirred);
223 struct tcf_t t;
224
225 opt.index = p->index;
226 opt.action = p->action;
227 opt.refcnt = p->refcnt - ref;
228 opt.bindcnt = p->bindcnt - bind;
229 opt.eaction = p->eaction;
230 opt.ifindex = p->ifindex;
231 DPRINTK("tcf_mirred_dump index %d action %d eaction %d ifindex %d\n",
232 p->index, p->action, p->eaction, p->ifindex);
233 RTA_PUT(skb, TCA_MIRRED_PARMS, sizeof(opt), &opt);
234 t.install = jiffies_to_clock_t(jiffies - p->tm.install);
235 t.lastuse = jiffies_to_clock_t(jiffies - p->tm.lastuse);
236 t.expires = jiffies_to_clock_t(p->tm.expires);
237 RTA_PUT(skb, TCA_MIRRED_TM, sizeof(t), &t);
238 return skb->len;
239
240 rtattr_failure:
241 skb_trim(skb, b - skb->data);
242 return -1;
243}
244
245static struct tc_action_ops act_mirred_ops = {
246 .kind = "mirred",
247 .type = TCA_ACT_MIRRED,
248 .capab = TCA_CAP_NONE,
249 .owner = THIS_MODULE,
250 .act = tcf_mirred,
251 .dump = tcf_mirred_dump,
252 .cleanup = tcf_mirred_cleanup,
253 .lookup = tcf_hash_search,
254 .init = tcf_mirred_init,
255 .walk = tcf_generic_walker
256};
257
258MODULE_AUTHOR("Jamal Hadi Salim(2002)");
259MODULE_DESCRIPTION("Device Mirror/redirect actions");
260MODULE_LICENSE("GPL");
261
262static int __init
263mirred_init_module(void)
264{
265 printk("Mirror/redirect action on\n");
266 return tcf_register_action(&act_mirred_ops);
267}
268
269static void __exit
270mirred_cleanup_module(void)
271{
272 tcf_unregister_action(&act_mirred_ops);
273}
274
275module_init(mirred_init_module);
276module_exit(mirred_cleanup_module);