xref: /linux/net/sched/sch_ingress.c (revision 2b8232ce512105e28453f301d1510de8363bccd1)
1 /* net/sched/sch_ingress.c - Ingress qdisc
2  *              This program is free software; you can redistribute it and/or
3  *              modify it under the terms of the GNU General Public License
4  *              as published by the Free Software Foundation; either version
5  *              2 of the License, or (at your option) any later version.
6  *
7  * Authors:     Jamal Hadi Salim 1999
8  */
9 
10 #include <linux/module.h>
11 #include <linux/types.h>
12 #include <linux/list.h>
13 #include <linux/skbuff.h>
14 #include <linux/rtnetlink.h>
15 #include <linux/netfilter_ipv4.h>
16 #include <linux/netfilter_ipv6.h>
17 #include <linux/netfilter.h>
18 #include <net/netlink.h>
19 #include <net/pkt_sched.h>
20 
21 
22 #undef DEBUG_INGRESS
23 
24 #ifdef DEBUG_INGRESS  /* control */
25 #define DPRINTK(format,args...) printk(KERN_DEBUG format,##args)
26 #else
27 #define DPRINTK(format,args...)
28 #endif
29 
30 #if 0  /* data */
31 #define D2PRINTK(format,args...) printk(KERN_DEBUG format,##args)
32 #else
33 #define D2PRINTK(format,args...)
34 #endif
35 
36 
37 #define PRIV(sch) qdisc_priv(sch)
38 
39 
40 /* Thanks to Doron Oz for this hack
41 */
42 #ifndef CONFIG_NET_CLS_ACT
43 #ifdef CONFIG_NETFILTER
44 static int nf_registered;
45 #endif
46 #endif
47 
48 struct ingress_qdisc_data {
49 	struct Qdisc		*q;
50 	struct tcf_proto	*filter_list;
51 };
52 
53 
54 /* ------------------------- Class/flow operations ------------------------- */
55 
56 
57 static int ingress_graft(struct Qdisc *sch,unsigned long arg,
58     struct Qdisc *new,struct Qdisc **old)
59 {
60 #ifdef DEBUG_INGRESS
61 	struct ingress_qdisc_data *p = PRIV(sch);
62 #endif
63 
64 	DPRINTK("ingress_graft(sch %p,[qdisc %p],new %p,old %p)\n",
65 		sch, p, new, old);
66 	DPRINTK("\n ingress_graft: You cannot add qdiscs to classes");
67 	return 1;
68 }
69 
70 
71 static struct Qdisc *ingress_leaf(struct Qdisc *sch, unsigned long arg)
72 {
73 	return NULL;
74 }
75 
76 
77 static unsigned long ingress_get(struct Qdisc *sch,u32 classid)
78 {
79 #ifdef DEBUG_INGRESS
80 	struct ingress_qdisc_data *p = PRIV(sch);
81 #endif
82 	DPRINTK("ingress_get(sch %p,[qdisc %p],classid %x)\n", sch, p, classid);
83 	return TC_H_MIN(classid) + 1;
84 }
85 
86 
87 static unsigned long ingress_bind_filter(struct Qdisc *sch,
88     unsigned long parent, u32 classid)
89 {
90 	return ingress_get(sch, classid);
91 }
92 
93 
94 static void ingress_put(struct Qdisc *sch, unsigned long cl)
95 {
96 }
97 
98 
99 static int ingress_change(struct Qdisc *sch, u32 classid, u32 parent,
100     struct rtattr **tca, unsigned long *arg)
101 {
102 #ifdef DEBUG_INGRESS
103 	struct ingress_qdisc_data *p = PRIV(sch);
104 #endif
105 	DPRINTK("ingress_change(sch %p,[qdisc %p],classid %x,parent %x),"
106 		"arg 0x%lx\n", sch, p, classid, parent, *arg);
107 	DPRINTK("No effect. sch_ingress doesn't maintain classes at the moment");
108 	return 0;
109 }
110 
111 
112 
113 static void ingress_walk(struct Qdisc *sch,struct qdisc_walker *walker)
114 {
115 #ifdef DEBUG_INGRESS
116 	struct ingress_qdisc_data *p = PRIV(sch);
117 #endif
118 	DPRINTK("ingress_walk(sch %p,[qdisc %p],walker %p)\n", sch, p, walker);
119 	DPRINTK("No effect. sch_ingress doesn't maintain classes at the moment");
120 }
121 
122 
123 static struct tcf_proto **ingress_find_tcf(struct Qdisc *sch,unsigned long cl)
124 {
125 	struct ingress_qdisc_data *p = PRIV(sch);
126 
127 	return &p->filter_list;
128 }
129 
130 
131 /* --------------------------- Qdisc operations ---------------------------- */
132 
133 
134 static int ingress_enqueue(struct sk_buff *skb,struct Qdisc *sch)
135 {
136 	struct ingress_qdisc_data *p = PRIV(sch);
137 	struct tcf_result res;
138 	int result;
139 
140 	D2PRINTK("ingress_enqueue(skb %p,sch %p,[qdisc %p])\n", skb, sch, p);
141 	result = tc_classify(skb, p->filter_list, &res);
142 	D2PRINTK("result %d class 0x%04x\n", result, res.classid);
143 	/*
144 	 * Unlike normal "enqueue" functions, ingress_enqueue returns a
145 	 * firewall FW_* code.
146 	 */
147 #ifdef CONFIG_NET_CLS_ACT
148 	sch->bstats.packets++;
149 	sch->bstats.bytes += skb->len;
150 	switch (result) {
151 		case TC_ACT_SHOT:
152 			result = TC_ACT_SHOT;
153 			sch->qstats.drops++;
154 			break;
155 		case TC_ACT_STOLEN:
156 		case TC_ACT_QUEUED:
157 			result = TC_ACT_STOLEN;
158 			break;
159 		case TC_ACT_RECLASSIFY:
160 		case TC_ACT_OK:
161 			skb->tc_index = TC_H_MIN(res.classid);
162 		default:
163 			result = TC_ACT_OK;
164 			break;
165 	}
166 #else
167 	D2PRINTK("Overriding result to ACCEPT\n");
168 	result = NF_ACCEPT;
169 	sch->bstats.packets++;
170 	sch->bstats.bytes += skb->len;
171 #endif
172 
173 	return result;
174 }
175 
176 
177 static struct sk_buff *ingress_dequeue(struct Qdisc *sch)
178 {
179 /*
180 	struct ingress_qdisc_data *p = PRIV(sch);
181 	D2PRINTK("ingress_dequeue(sch %p,[qdisc %p])\n",sch,PRIV(p));
182 */
183 	return NULL;
184 }
185 
186 
187 static int ingress_requeue(struct sk_buff *skb,struct Qdisc *sch)
188 {
189 /*
190 	struct ingress_qdisc_data *p = PRIV(sch);
191 	D2PRINTK("ingress_requeue(skb %p,sch %p,[qdisc %p])\n",skb,sch,PRIV(p));
192 */
193 	return 0;
194 }
195 
196 static unsigned int ingress_drop(struct Qdisc *sch)
197 {
198 #ifdef DEBUG_INGRESS
199 	struct ingress_qdisc_data *p = PRIV(sch);
200 #endif
201 	DPRINTK("ingress_drop(sch %p,[qdisc %p])\n", sch, p);
202 	return 0;
203 }
204 
205 #ifndef CONFIG_NET_CLS_ACT
206 #ifdef CONFIG_NETFILTER
207 static unsigned int
208 ing_hook(unsigned int hook, struct sk_buff **pskb,
209 			     const struct net_device *indev,
210 			     const struct net_device *outdev,
211 			     int (*okfn)(struct sk_buff *))
212 {
213 
214 	struct Qdisc *q;
215 	struct sk_buff *skb = *pskb;
216 	struct net_device *dev = skb->dev;
217 	int fwres=NF_ACCEPT;
218 
219 	DPRINTK("ing_hook: skb %s dev=%s len=%u\n",
220 		skb->sk ? "(owned)" : "(unowned)",
221 		skb->dev ? (*pskb)->dev->name : "(no dev)",
222 		skb->len);
223 
224 	if (dev->qdisc_ingress) {
225 		spin_lock(&dev->ingress_lock);
226 		if ((q = dev->qdisc_ingress) != NULL)
227 			fwres = q->enqueue(skb, q);
228 		spin_unlock(&dev->ingress_lock);
229 	}
230 
231 	return fwres;
232 }
233 
234 /* after ipt_filter */
235 static struct nf_hook_ops ing_ops = {
236 	.hook           = ing_hook,
237 	.owner		= THIS_MODULE,
238 	.pf             = PF_INET,
239 	.hooknum        = NF_IP_PRE_ROUTING,
240 	.priority       = NF_IP_PRI_FILTER + 1,
241 };
242 
243 static struct nf_hook_ops ing6_ops = {
244 	.hook           = ing_hook,
245 	.owner		= THIS_MODULE,
246 	.pf             = PF_INET6,
247 	.hooknum        = NF_IP6_PRE_ROUTING,
248 	.priority       = NF_IP6_PRI_FILTER + 1,
249 };
250 
251 #endif
252 #endif
253 
254 static int ingress_init(struct Qdisc *sch,struct rtattr *opt)
255 {
256 	struct ingress_qdisc_data *p = PRIV(sch);
257 
258 /* Make sure either netfilter or preferably CLS_ACT is
259 * compiled in */
260 #ifndef CONFIG_NET_CLS_ACT
261 #ifndef CONFIG_NETFILTER
262 	printk("You MUST compile classifier actions into the kernel\n");
263 	return -EINVAL;
264 #else
265 	printk("Ingress scheduler: Classifier actions prefered over netfilter\n");
266 #endif
267 #endif
268 
269 #ifndef CONFIG_NET_CLS_ACT
270 #ifdef CONFIG_NETFILTER
271 	if (!nf_registered) {
272 		if (nf_register_hook(&ing_ops) < 0) {
273 			printk("ingress qdisc registration error \n");
274 			return -EINVAL;
275 		}
276 		nf_registered++;
277 
278 		if (nf_register_hook(&ing6_ops) < 0) {
279 			printk("IPv6 ingress qdisc registration error, " \
280 			    "disabling IPv6 support.\n");
281 		} else
282 			nf_registered++;
283 	}
284 #endif
285 #endif
286 
287 	DPRINTK("ingress_init(sch %p,[qdisc %p],opt %p)\n",sch,p,opt);
288 	p->q = &noop_qdisc;
289 	return 0;
290 }
291 
292 
293 static void ingress_reset(struct Qdisc *sch)
294 {
295 	struct ingress_qdisc_data *p = PRIV(sch);
296 
297 	DPRINTK("ingress_reset(sch %p,[qdisc %p])\n", sch, p);
298 
299 /*
300 #if 0
301 */
302 /* for future use */
303 	qdisc_reset(p->q);
304 /*
305 #endif
306 */
307 }
308 
309 /* ------------------------------------------------------------- */
310 
311 
312 /* ------------------------------------------------------------- */
313 
314 static void ingress_destroy(struct Qdisc *sch)
315 {
316 	struct ingress_qdisc_data *p = PRIV(sch);
317 
318 	DPRINTK("ingress_destroy(sch %p,[qdisc %p])\n", sch, p);
319 	tcf_destroy_chain(p->filter_list);
320 #if 0
321 /* for future use */
322 	qdisc_destroy(p->q);
323 #endif
324 }
325 
326 
327 static int ingress_dump(struct Qdisc *sch, struct sk_buff *skb)
328 {
329 	unsigned char *b = skb_tail_pointer(skb);
330 	struct rtattr *rta;
331 
332 	rta = (struct rtattr *) b;
333 	RTA_PUT(skb, TCA_OPTIONS, 0, NULL);
334 	rta->rta_len = skb_tail_pointer(skb) - b;
335 	return skb->len;
336 
337 rtattr_failure:
338 	nlmsg_trim(skb, b);
339 	return -1;
340 }
341 
342 static struct Qdisc_class_ops ingress_class_ops = {
343 	.graft		=	ingress_graft,
344 	.leaf		=	ingress_leaf,
345 	.get		=	ingress_get,
346 	.put		=	ingress_put,
347 	.change		=	ingress_change,
348 	.delete		=	NULL,
349 	.walk		=	ingress_walk,
350 	.tcf_chain	=	ingress_find_tcf,
351 	.bind_tcf	=	ingress_bind_filter,
352 	.unbind_tcf	=	ingress_put,
353 	.dump		=	NULL,
354 };
355 
356 static struct Qdisc_ops ingress_qdisc_ops = {
357 	.next		=	NULL,
358 	.cl_ops		=	&ingress_class_ops,
359 	.id		=	"ingress",
360 	.priv_size	=	sizeof(struct ingress_qdisc_data),
361 	.enqueue	=	ingress_enqueue,
362 	.dequeue	=	ingress_dequeue,
363 	.requeue	=	ingress_requeue,
364 	.drop		=	ingress_drop,
365 	.init		=	ingress_init,
366 	.reset		=	ingress_reset,
367 	.destroy	=	ingress_destroy,
368 	.change		=	NULL,
369 	.dump		=	ingress_dump,
370 	.owner		=	THIS_MODULE,
371 };
372 
373 static int __init ingress_module_init(void)
374 {
375 	int ret = 0;
376 
377 	if ((ret = register_qdisc(&ingress_qdisc_ops)) < 0) {
378 		printk("Unable to register Ingress qdisc\n");
379 		return ret;
380 	}
381 
382 	return ret;
383 }
384 static void __exit ingress_module_exit(void)
385 {
386 	unregister_qdisc(&ingress_qdisc_ops);
387 #ifndef CONFIG_NET_CLS_ACT
388 #ifdef CONFIG_NETFILTER
389 	if (nf_registered) {
390 		nf_unregister_hook(&ing_ops);
391 		if (nf_registered > 1)
392 			nf_unregister_hook(&ing6_ops);
393 	}
394 #endif
395 #endif
396 }
397 module_init(ingress_module_init)
398 module_exit(ingress_module_exit)
399 MODULE_LICENSE("GPL");
400