xref: /openbmc/linux/net/sched/sch_ingress.c (revision c21b37f6)
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 		case TC_ACT_UNSPEC:
162 		default:
163 			skb->tc_index = TC_H_MIN(res.classid);
164 			result = TC_ACT_OK;
165 			break;
166 	}
167 #else
168 	D2PRINTK("Overriding result to ACCEPT\n");
169 	result = NF_ACCEPT;
170 	sch->bstats.packets++;
171 	sch->bstats.bytes += skb->len;
172 #endif
173 
174 	return result;
175 }
176 
177 
178 static struct sk_buff *ingress_dequeue(struct Qdisc *sch)
179 {
180 /*
181 	struct ingress_qdisc_data *p = PRIV(sch);
182 	D2PRINTK("ingress_dequeue(sch %p,[qdisc %p])\n",sch,PRIV(p));
183 */
184 	return NULL;
185 }
186 
187 
188 static int ingress_requeue(struct sk_buff *skb,struct Qdisc *sch)
189 {
190 /*
191 	struct ingress_qdisc_data *p = PRIV(sch);
192 	D2PRINTK("ingress_requeue(skb %p,sch %p,[qdisc %p])\n",skb,sch,PRIV(p));
193 */
194 	return 0;
195 }
196 
197 static unsigned int ingress_drop(struct Qdisc *sch)
198 {
199 #ifdef DEBUG_INGRESS
200 	struct ingress_qdisc_data *p = PRIV(sch);
201 #endif
202 	DPRINTK("ingress_drop(sch %p,[qdisc %p])\n", sch, p);
203 	return 0;
204 }
205 
206 #ifndef CONFIG_NET_CLS_ACT
207 #ifdef CONFIG_NETFILTER
208 static unsigned int
209 ing_hook(unsigned int hook, struct sk_buff **pskb,
210 			     const struct net_device *indev,
211 			     const struct net_device *outdev,
212 			     int (*okfn)(struct sk_buff *))
213 {
214 
215 	struct Qdisc *q;
216 	struct sk_buff *skb = *pskb;
217 	struct net_device *dev = skb->dev;
218 	int fwres=NF_ACCEPT;
219 
220 	DPRINTK("ing_hook: skb %s dev=%s len=%u\n",
221 		skb->sk ? "(owned)" : "(unowned)",
222 		skb->dev ? (*pskb)->dev->name : "(no dev)",
223 		skb->len);
224 
225 	if (dev->qdisc_ingress) {
226 		spin_lock(&dev->ingress_lock);
227 		if ((q = dev->qdisc_ingress) != NULL)
228 			fwres = q->enqueue(skb, q);
229 		spin_unlock(&dev->ingress_lock);
230 	}
231 
232 	return fwres;
233 }
234 
235 /* after ipt_filter */
236 static struct nf_hook_ops ing_ops = {
237 	.hook           = ing_hook,
238 	.owner		= THIS_MODULE,
239 	.pf             = PF_INET,
240 	.hooknum        = NF_IP_PRE_ROUTING,
241 	.priority       = NF_IP_PRI_FILTER + 1,
242 };
243 
244 static struct nf_hook_ops ing6_ops = {
245 	.hook           = ing_hook,
246 	.owner		= THIS_MODULE,
247 	.pf             = PF_INET6,
248 	.hooknum        = NF_IP6_PRE_ROUTING,
249 	.priority       = NF_IP6_PRI_FILTER + 1,
250 };
251 
252 #endif
253 #endif
254 
255 static int ingress_init(struct Qdisc *sch,struct rtattr *opt)
256 {
257 	struct ingress_qdisc_data *p = PRIV(sch);
258 
259 /* Make sure either netfilter or preferably CLS_ACT is
260 * compiled in */
261 #ifndef CONFIG_NET_CLS_ACT
262 #ifndef CONFIG_NETFILTER
263 	printk("You MUST compile classifier actions into the kernel\n");
264 	return -EINVAL;
265 #else
266 	printk("Ingress scheduler: Classifier actions prefered over netfilter\n");
267 #endif
268 #endif
269 
270 #ifndef CONFIG_NET_CLS_ACT
271 #ifdef CONFIG_NETFILTER
272 	if (!nf_registered) {
273 		if (nf_register_hook(&ing_ops) < 0) {
274 			printk("ingress qdisc registration error \n");
275 			return -EINVAL;
276 		}
277 		nf_registered++;
278 
279 		if (nf_register_hook(&ing6_ops) < 0) {
280 			printk("IPv6 ingress qdisc registration error, " \
281 			    "disabling IPv6 support.\n");
282 		} else
283 			nf_registered++;
284 	}
285 #endif
286 #endif
287 
288 	DPRINTK("ingress_init(sch %p,[qdisc %p],opt %p)\n",sch,p,opt);
289 	p->q = &noop_qdisc;
290 	return 0;
291 }
292 
293 
294 static void ingress_reset(struct Qdisc *sch)
295 {
296 	struct ingress_qdisc_data *p = PRIV(sch);
297 
298 	DPRINTK("ingress_reset(sch %p,[qdisc %p])\n", sch, p);
299 
300 /*
301 #if 0
302 */
303 /* for future use */
304 	qdisc_reset(p->q);
305 /*
306 #endif
307 */
308 }
309 
310 /* ------------------------------------------------------------- */
311 
312 
313 /* ------------------------------------------------------------- */
314 
315 static void ingress_destroy(struct Qdisc *sch)
316 {
317 	struct ingress_qdisc_data *p = PRIV(sch);
318 
319 	DPRINTK("ingress_destroy(sch %p,[qdisc %p])\n", sch, p);
320 	tcf_destroy_chain(p->filter_list);
321 #if 0
322 /* for future use */
323 	qdisc_destroy(p->q);
324 #endif
325 }
326 
327 
328 static int ingress_dump(struct Qdisc *sch, struct sk_buff *skb)
329 {
330 	unsigned char *b = skb_tail_pointer(skb);
331 	struct rtattr *rta;
332 
333 	rta = (struct rtattr *) b;
334 	RTA_PUT(skb, TCA_OPTIONS, 0, NULL);
335 	rta->rta_len = skb_tail_pointer(skb) - b;
336 	return skb->len;
337 
338 rtattr_failure:
339 	nlmsg_trim(skb, b);
340 	return -1;
341 }
342 
343 static struct Qdisc_class_ops ingress_class_ops = {
344 	.graft		=	ingress_graft,
345 	.leaf		=	ingress_leaf,
346 	.get		=	ingress_get,
347 	.put		=	ingress_put,
348 	.change		=	ingress_change,
349 	.delete		=	NULL,
350 	.walk		=	ingress_walk,
351 	.tcf_chain	=	ingress_find_tcf,
352 	.bind_tcf	=	ingress_bind_filter,
353 	.unbind_tcf	=	ingress_put,
354 	.dump		=	NULL,
355 };
356 
357 static struct Qdisc_ops ingress_qdisc_ops = {
358 	.next		=	NULL,
359 	.cl_ops		=	&ingress_class_ops,
360 	.id		=	"ingress",
361 	.priv_size	=	sizeof(struct ingress_qdisc_data),
362 	.enqueue	=	ingress_enqueue,
363 	.dequeue	=	ingress_dequeue,
364 	.requeue	=	ingress_requeue,
365 	.drop		=	ingress_drop,
366 	.init		=	ingress_init,
367 	.reset		=	ingress_reset,
368 	.destroy	=	ingress_destroy,
369 	.change		=	NULL,
370 	.dump		=	ingress_dump,
371 	.owner		=	THIS_MODULE,
372 };
373 
374 static int __init ingress_module_init(void)
375 {
376 	int ret = 0;
377 
378 	if ((ret = register_qdisc(&ingress_qdisc_ops)) < 0) {
379 		printk("Unable to register Ingress qdisc\n");
380 		return ret;
381 	}
382 
383 	return ret;
384 }
385 static void __exit ingress_module_exit(void)
386 {
387 	unregister_qdisc(&ingress_qdisc_ops);
388 #ifndef CONFIG_NET_CLS_ACT
389 #ifdef CONFIG_NETFILTER
390 	if (nf_registered) {
391 		nf_unregister_hook(&ing_ops);
392 		if (nf_registered > 1)
393 			nf_unregister_hook(&ing6_ops);
394 	}
395 #endif
396 #endif
397 }
398 module_init(ingress_module_init)
399 module_exit(ingress_module_exit)
400 MODULE_LICENSE("GPL");
401