xref: /openbmc/linux/net/sched/sch_ingress.c (revision 1da177e4c3f41524e886b7f1b8a0c1fc7321cac2)
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/config.h>
11 #include <linux/module.h>
12 #include <linux/types.h>
13 #include <linux/skbuff.h>
14 #include <linux/netdevice.h>
15 #include <linux/rtnetlink.h>
16 #include <linux/netfilter_ipv4.h>
17 #include <linux/netfilter_ipv6.h>
18 #include <linux/netfilter.h>
19 #include <linux/smp.h>
20 #include <net/pkt_sched.h>
21 #include <asm/byteorder.h>
22 #include <asm/uaccess.h>
23 #include <linux/kmod.h>
24 #include <linux/stat.h>
25 #include <linux/interrupt.h>
26 #include <linux/list.h>
27 
28 
29 #undef DEBUG_INGRESS
30 
31 #ifdef DEBUG_INGRESS  /* control */
32 #define DPRINTK(format,args...) printk(KERN_DEBUG format,##args)
33 #else
34 #define DPRINTK(format,args...)
35 #endif
36 
37 #if 0  /* data */
38 #define D2PRINTK(format,args...) printk(KERN_DEBUG format,##args)
39 #else
40 #define D2PRINTK(format,args...)
41 #endif
42 
43 
44 #define PRIV(sch) qdisc_priv(sch)
45 
46 
47 /* Thanks to Doron Oz for this hack
48 */
49 #ifndef CONFIG_NET_CLS_ACT
50 #ifdef CONFIG_NETFILTER
51 static int nf_registered;
52 #endif
53 #endif
54 
55 struct ingress_qdisc_data {
56 	struct Qdisc		*q;
57 	struct tcf_proto	*filter_list;
58 };
59 
60 
61 /* ------------------------- Class/flow operations ------------------------- */
62 
63 
64 static int ingress_graft(struct Qdisc *sch,unsigned long arg,
65     struct Qdisc *new,struct Qdisc **old)
66 {
67 #ifdef DEBUG_INGRESS
68 	struct ingress_qdisc_data *p = PRIV(sch);
69 #endif
70 
71 	DPRINTK("ingress_graft(sch %p,[qdisc %p],new %p,old %p)\n",
72 		sch, p, new, old);
73 	DPRINTK("\n ingress_graft: You cannot add qdiscs to classes");
74         return 1;
75 }
76 
77 
78 static struct Qdisc *ingress_leaf(struct Qdisc *sch, unsigned long arg)
79 {
80 	return NULL;
81 }
82 
83 
84 static unsigned long ingress_get(struct Qdisc *sch,u32 classid)
85 {
86 #ifdef DEBUG_INGRESS
87 	struct ingress_qdisc_data *p = PRIV(sch);
88 #endif
89 	DPRINTK("ingress_get(sch %p,[qdisc %p],classid %x)\n", sch, p, classid);
90 	return TC_H_MIN(classid) + 1;
91 }
92 
93 
94 static unsigned long ingress_bind_filter(struct Qdisc *sch,
95     unsigned long parent, u32 classid)
96 {
97 	return ingress_get(sch, classid);
98 }
99 
100 
101 static void ingress_put(struct Qdisc *sch, unsigned long cl)
102 {
103 }
104 
105 
106 static int ingress_change(struct Qdisc *sch, u32 classid, u32 parent,
107     struct rtattr **tca, unsigned long *arg)
108 {
109 #ifdef DEBUG_INGRESS
110 	struct ingress_qdisc_data *p = PRIV(sch);
111 #endif
112 	DPRINTK("ingress_change(sch %p,[qdisc %p],classid %x,parent %x),"
113 		"arg 0x%lx\n", sch, p, classid, parent, *arg);
114 	DPRINTK("No effect. sch_ingress doesn't maintain classes at the moment");
115 	return 0;
116 }
117 
118 
119 
120 static void ingress_walk(struct Qdisc *sch,struct qdisc_walker *walker)
121 {
122 #ifdef DEBUG_INGRESS
123 	struct ingress_qdisc_data *p = PRIV(sch);
124 #endif
125 	DPRINTK("ingress_walk(sch %p,[qdisc %p],walker %p)\n", sch, p, walker);
126 	DPRINTK("No effect. sch_ingress doesn't maintain classes at the moment");
127 }
128 
129 
130 static struct tcf_proto **ingress_find_tcf(struct Qdisc *sch,unsigned long cl)
131 {
132 	struct ingress_qdisc_data *p = PRIV(sch);
133 
134 	return &p->filter_list;
135 }
136 
137 
138 /* --------------------------- Qdisc operations ---------------------------- */
139 
140 
141 static int ingress_enqueue(struct sk_buff *skb,struct Qdisc *sch)
142 {
143 	struct ingress_qdisc_data *p = PRIV(sch);
144 	struct tcf_result res;
145 	int result;
146 
147 	D2PRINTK("ingress_enqueue(skb %p,sch %p,[qdisc %p])\n", skb, sch, p);
148 	result = tc_classify(skb, p->filter_list, &res);
149 	D2PRINTK("result %d class 0x%04x\n", result, res.classid);
150 	/*
151 	 * Unlike normal "enqueue" functions, ingress_enqueue returns a
152 	 * firewall FW_* code.
153 	 */
154 #ifdef CONFIG_NET_CLS_ACT
155 	sch->bstats.packets++;
156 	sch->bstats.bytes += skb->len;
157 	switch (result) {
158 		case TC_ACT_SHOT:
159 			result = TC_ACT_SHOT;
160 			sch->qstats.drops++;
161 			break;
162 		case TC_ACT_STOLEN:
163 		case TC_ACT_QUEUED:
164 			result = TC_ACT_STOLEN;
165 			break;
166 		case TC_ACT_RECLASSIFY:
167 		case TC_ACT_OK:
168 		case TC_ACT_UNSPEC:
169 		default:
170 			skb->tc_index = TC_H_MIN(res.classid);
171 			result = TC_ACT_OK;
172 			break;
173 	};
174 /* backward compat */
175 #else
176 #ifdef	CONFIG_NET_CLS_POLICE
177 	switch (result) {
178 		case TC_POLICE_SHOT:
179 		result = NF_DROP;
180 		sch->qstats.drops++;
181 		break;
182 		case TC_POLICE_RECLASSIFY: /* DSCP remarking here ? */
183 		case TC_POLICE_OK:
184 		case TC_POLICE_UNSPEC:
185 		default:
186 		sch->bstats.packets++;
187 		sch->bstats.bytes += skb->len;
188 		result = NF_ACCEPT;
189 		break;
190 	};
191 
192 #else
193 	D2PRINTK("Overriding result to ACCEPT\n");
194 	result = NF_ACCEPT;
195 	sch->bstats.packets++;
196 	sch->bstats.bytes += skb->len;
197 #endif
198 #endif
199 
200 	return result;
201 }
202 
203 
204 static struct sk_buff *ingress_dequeue(struct Qdisc *sch)
205 {
206 /*
207 	struct ingress_qdisc_data *p = PRIV(sch);
208 	D2PRINTK("ingress_dequeue(sch %p,[qdisc %p])\n",sch,PRIV(p));
209 */
210 	return NULL;
211 }
212 
213 
214 static int ingress_requeue(struct sk_buff *skb,struct Qdisc *sch)
215 {
216 /*
217 	struct ingress_qdisc_data *p = PRIV(sch);
218 	D2PRINTK("ingress_requeue(skb %p,sch %p,[qdisc %p])\n",skb,sch,PRIV(p));
219 */
220 	return 0;
221 }
222 
223 static unsigned int ingress_drop(struct Qdisc *sch)
224 {
225 #ifdef DEBUG_INGRESS
226 	struct ingress_qdisc_data *p = PRIV(sch);
227 #endif
228 	DPRINTK("ingress_drop(sch %p,[qdisc %p])\n", sch, p);
229 	return 0;
230 }
231 
232 #ifndef CONFIG_NET_CLS_ACT
233 #ifdef CONFIG_NETFILTER
234 static unsigned int
235 ing_hook(unsigned int hook, struct sk_buff **pskb,
236                              const struct net_device *indev,
237                              const struct net_device *outdev,
238 	                     int (*okfn)(struct sk_buff *))
239 {
240 
241 	struct Qdisc *q;
242 	struct sk_buff *skb = *pskb;
243         struct net_device *dev = skb->dev;
244 	int fwres=NF_ACCEPT;
245 
246 	DPRINTK("ing_hook: skb %s dev=%s len=%u\n",
247 		skb->sk ? "(owned)" : "(unowned)",
248 		skb->dev ? (*pskb)->dev->name : "(no dev)",
249 		skb->len);
250 
251 /*
252 revisit later: Use a private since lock dev->queue_lock is also
253 used on the egress (might slow things for an iota)
254 */
255 
256 	if (dev->qdisc_ingress) {
257 		spin_lock(&dev->queue_lock);
258 		if ((q = dev->qdisc_ingress) != NULL)
259 			fwres = q->enqueue(skb, q);
260 		spin_unlock(&dev->queue_lock);
261         }
262 
263 	return fwres;
264 }
265 
266 /* after ipt_filter */
267 static struct nf_hook_ops ing_ops = {
268 	.hook           = ing_hook,
269 	.owner		= THIS_MODULE,
270 	.pf             = PF_INET,
271 	.hooknum        = NF_IP_PRE_ROUTING,
272 	.priority       = NF_IP_PRI_FILTER + 1,
273 };
274 
275 static struct nf_hook_ops ing6_ops = {
276 	.hook           = ing_hook,
277 	.owner		= THIS_MODULE,
278 	.pf             = PF_INET6,
279 	.hooknum        = NF_IP6_PRE_ROUTING,
280 	.priority       = NF_IP6_PRI_FILTER + 1,
281 };
282 
283 #endif
284 #endif
285 
286 static int ingress_init(struct Qdisc *sch,struct rtattr *opt)
287 {
288 	struct ingress_qdisc_data *p = PRIV(sch);
289 
290 /* Make sure either netfilter or preferably CLS_ACT is
291 * compiled in */
292 #ifndef CONFIG_NET_CLS_ACT
293 #ifndef CONFIG_NETFILTER
294 	printk("You MUST compile classifier actions into the kernel\n");
295 	return -EINVAL;
296 #else
297 	printk("Ingress scheduler: Classifier actions prefered over netfilter\n");
298 #endif
299 #endif
300 
301 #ifndef CONFIG_NET_CLS_ACT
302 #ifdef CONFIG_NETFILTER
303 	if (!nf_registered) {
304 		if (nf_register_hook(&ing_ops) < 0) {
305 			printk("ingress qdisc registration error \n");
306 			return -EINVAL;
307 		}
308 		nf_registered++;
309 
310 		if (nf_register_hook(&ing6_ops) < 0) {
311 			printk("IPv6 ingress qdisc registration error, " \
312 			    "disabling IPv6 support.\n");
313 		} else
314 			nf_registered++;
315 	}
316 #endif
317 #endif
318 
319 	DPRINTK("ingress_init(sch %p,[qdisc %p],opt %p)\n",sch,p,opt);
320 	p->q = &noop_qdisc;
321 	return 0;
322 }
323 
324 
325 static void ingress_reset(struct Qdisc *sch)
326 {
327 	struct ingress_qdisc_data *p = PRIV(sch);
328 
329 	DPRINTK("ingress_reset(sch %p,[qdisc %p])\n", sch, p);
330 
331 /*
332 #if 0
333 */
334 /* for future use */
335 	qdisc_reset(p->q);
336 /*
337 #endif
338 */
339 }
340 
341 /* ------------------------------------------------------------- */
342 
343 
344 /* ------------------------------------------------------------- */
345 
346 static void ingress_destroy(struct Qdisc *sch)
347 {
348 	struct ingress_qdisc_data *p = PRIV(sch);
349 	struct tcf_proto *tp;
350 
351 	DPRINTK("ingress_destroy(sch %p,[qdisc %p])\n", sch, p);
352 	while (p->filter_list) {
353 		tp = p->filter_list;
354 		p->filter_list = tp->next;
355 		tcf_destroy(tp);
356 	}
357 #if 0
358 /* for future use */
359 	qdisc_destroy(p->q);
360 #endif
361 }
362 
363 
364 static int ingress_dump(struct Qdisc *sch, struct sk_buff *skb)
365 {
366 	unsigned char *b = skb->tail;
367 	struct rtattr *rta;
368 
369 	rta = (struct rtattr *) b;
370 	RTA_PUT(skb, TCA_OPTIONS, 0, NULL);
371 	rta->rta_len = skb->tail - b;
372 	return skb->len;
373 
374 rtattr_failure:
375 	skb_trim(skb, b - skb->data);
376 	return -1;
377 }
378 
379 static struct Qdisc_class_ops ingress_class_ops = {
380 	.graft		=	ingress_graft,
381 	.leaf		=	ingress_leaf,
382 	.get		=	ingress_get,
383 	.put		=	ingress_put,
384 	.change		=	ingress_change,
385 	.delete		=	NULL,
386 	.walk		=	ingress_walk,
387 	.tcf_chain	=	ingress_find_tcf,
388 	.bind_tcf	=	ingress_bind_filter,
389 	.unbind_tcf	=	ingress_put,
390 	.dump		=	NULL,
391 };
392 
393 static struct Qdisc_ops ingress_qdisc_ops = {
394 	.next		=	NULL,
395 	.cl_ops		=	&ingress_class_ops,
396 	.id		=	"ingress",
397 	.priv_size	=	sizeof(struct ingress_qdisc_data),
398 	.enqueue	=	ingress_enqueue,
399 	.dequeue	=	ingress_dequeue,
400 	.requeue	=	ingress_requeue,
401 	.drop		=	ingress_drop,
402 	.init		=	ingress_init,
403 	.reset		=	ingress_reset,
404 	.destroy	=	ingress_destroy,
405 	.change		=	NULL,
406 	.dump		=	ingress_dump,
407 	.owner		=	THIS_MODULE,
408 };
409 
410 static int __init ingress_module_init(void)
411 {
412 	int ret = 0;
413 
414 	if ((ret = register_qdisc(&ingress_qdisc_ops)) < 0) {
415 		printk("Unable to register Ingress qdisc\n");
416 		return ret;
417 	}
418 
419 	return ret;
420 }
421 static void __exit ingress_module_exit(void)
422 {
423 	unregister_qdisc(&ingress_qdisc_ops);
424 #ifndef CONFIG_NET_CLS_ACT
425 #ifdef CONFIG_NETFILTER
426 	if (nf_registered) {
427 		nf_unregister_hook(&ing_ops);
428 		if (nf_registered > 1)
429 			nf_unregister_hook(&ing6_ops);
430 	}
431 #endif
432 #endif
433 }
434 module_init(ingress_module_init)
435 module_exit(ingress_module_exit)
436 MODULE_LICENSE("GPL");
437