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   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 /* Thanks to Doron Oz for this hack */
  23 #ifndef CONFIG_NET_CLS_ACT
  24 #ifdef CONFIG_NETFILTER
  25 static int nf_registered;
  26 #endif
  27 #endif
  28
  29 struct ingress_qdisc_data {
  30         struct tcf_proto        *filter_list;
  31 };
  32
  33 /* ------------------------- Class/flow operations ------------------------- */
  34
  35 static int ingress_graft(struct Qdisc *sch, unsigned long arg,
  36                          struct Qdisc *new, struct Qdisc **old)
  37 {
  38         return 1;
  39 }
  40
  41 static struct Qdisc *ingress_leaf(struct Qdisc *sch, unsigned long arg)
  42 {
  43         return NULL;
  44 }
  45
  46 static unsigned long ingress_get(struct Qdisc *sch, u32 classid)
  47 {
  48         return TC_H_MIN(classid) + 1;
  49 }
  50
  51 static unsigned long ingress_bind_filter(struct Qdisc *sch,
  52                                          unsigned long parent, u32 classid)
  53 {
  54         return ingress_get(sch, classid);
  55 }
  56
  57 static void ingress_put(struct Qdisc *sch, unsigned long cl)
  58 {
  59 }
  60
  61 static int ingress_change(struct Qdisc *sch, u32 classid, u32 parent,
  62                           struct rtattr **tca, unsigned long *arg)
  63 {
  64         return 0;
  65 }
  66
  67 static void ingress_walk(struct Qdisc *sch, struct qdisc_walker *walker)
  68 {
  69         return;
  70 }
  71
  72 static struct tcf_proto **ingress_find_tcf(struct Qdisc *sch, unsigned long cl)
  73 {
  74         struct ingress_qdisc_data *p = qdisc_priv(sch);
  75
  76         return &p->filter_list;
  77 }
  78
  79 /* --------------------------- Qdisc operations ---------------------------- */
  80
  81 static int ingress_enqueue(struct sk_buff *skb, struct Qdisc *sch)
  82 {
  83         struct ingress_qdisc_data *p = qdisc_priv(sch);
  84         struct tcf_result res;
  85         int result;
  86
  87         result = tc_classify(skb, p->filter_list, &res);
  88
  89         /*
  90          * Unlike normal "enqueue" functions, ingress_enqueue returns a
  91          * firewall FW_* code.
  92          */
  93 #ifdef CONFIG_NET_CLS_ACT
  94         sch->bstats.packets++;
  95         sch->bstats.bytes += skb->len;
  96         switch (result) {
  97         case TC_ACT_SHOT:
  98                 result = TC_ACT_SHOT;
  99                 sch->qstats.drops++;
 100                 break;
 101         case TC_ACT_STOLEN:
 102         case TC_ACT_QUEUED:
 103                 result = TC_ACT_STOLEN;
 104                 break;
 105         case TC_ACT_RECLASSIFY:
 106         case TC_ACT_OK:
 107                 skb->tc_index = TC_H_MIN(res.classid);
 108         default:
 109                 result = TC_ACT_OK;
 110                 break;
 111         }
 112 #else
 113         result = NF_ACCEPT;
 114         sch->bstats.packets++;
 115         sch->bstats.bytes += skb->len;
 116 #endif
 117
 118         return result;
 119 }
 120
 121 static struct sk_buff *ingress_dequeue(struct Qdisc *sch)
 122 {
 123         return NULL;
 124 }
 125
 126 static int ingress_requeue(struct sk_buff *skb, struct Qdisc *sch)
 127 {
 128         return 0;
 129 }
 130
 131 static unsigned int ingress_drop(struct Qdisc *sch)
 132 {
 133         return 0;
 134 }
 135
 136 #ifndef CONFIG_NET_CLS_ACT
 137 #ifdef CONFIG_NETFILTER
 138 static unsigned int ing_hook(unsigned int hook, struct sk_buff *skb,
 139                              const struct net_device *indev,
 140                              const struct net_device *outdev,
 141                              int (*okfn)(struct sk_buff *))
 142 {
 143
 144         struct Qdisc *q;
 145         struct net_device *dev = skb->dev;
 146         int fwres = NF_ACCEPT;
 147
 148         if (dev->qdisc_ingress) {
 149                 spin_lock(&dev->ingress_lock);
 150                 if ((q = dev->qdisc_ingress) != NULL)
 151                         fwres = q->enqueue(skb, q);
 152                 spin_unlock(&dev->ingress_lock);
 153         }
 154
 155         return fwres;
 156 }
 157
 158 /* after ipt_filter */
 159 static struct nf_hook_ops ing_ops[] __read_mostly = {
 160         {
 161                 .hook           = ing_hook,
 162                 .owner          = THIS_MODULE,
 163                 .pf             = PF_INET,
 164                 .hooknum        = NF_INET_PRE_ROUTING,
 165                 .priority       = NF_IP_PRI_FILTER + 1,
 166         },
 167         {
 168                 .hook           = ing_hook,
 169                 .owner          = THIS_MODULE,
 170                 .pf             = PF_INET6,
 171                 .hooknum        = NF_INET_PRE_ROUTING,
 172                 .priority       = NF_IP6_PRI_FILTER + 1,
 173         },
 174 };
 175 #endif
 176 #endif
 177
 178 static int ingress_init(struct Qdisc *sch, struct rtattr *opt)
 179 {
 180         /* Make sure either netfilter or preferably CLS_ACT is
 181          * compiled in */
 182 #ifndef CONFIG_NET_CLS_ACT
 183 #ifndef CONFIG_NETFILTER
 184         printk("You MUST compile classifier actions into the kernel\n");
 185         return -EINVAL;
 186 #else
 187         printk("Ingress scheduler: Classifier actions prefered over netfilter\n");
 188 #endif
 189 #endif
 190
 191 #ifndef CONFIG_NET_CLS_ACT
 192 #ifdef CONFIG_NETFILTER
 193         if (!nf_registered) {
 194                 if (nf_register_hooks(ing_ops, ARRAY_SIZE(ing_ops)) < 0) {
 195                         printk("ingress qdisc registration error \n");
 196                         return -EINVAL;
 197                 }
 198                 nf_registered++;
 199         }
 200 #endif
 201 #endif
 202         return 0;
 203 }
 204
 205 static void ingress_reset(struct Qdisc *sch)
 206 {
 207         return;
 208 }
 209
 210 /* ------------------------------------------------------------- */
 211
 212 static void ingress_destroy(struct Qdisc *sch)
 213 {
 214         struct ingress_qdisc_data *p = qdisc_priv(sch);
 215
 216         tcf_destroy_chain(p->filter_list);
 217 }
 218
 219 static int ingress_dump(struct Qdisc *sch, struct sk_buff *skb)
 220 {
 221         unsigned char *b = skb_tail_pointer(skb);
 222         struct rtattr *rta;
 223
 224         rta = (struct rtattr *)b;
 225         RTA_PUT(skb, TCA_OPTIONS, 0, NULL);
 226         rta->rta_len = skb_tail_pointer(skb) - b;
 227         return skb->len;
 228
 229 rtattr_failure:
 230         nlmsg_trim(skb, b);
 231         return -1;
 232 }
 233
 234 static const struct Qdisc_class_ops ingress_class_ops = {
 235         .graft          =       ingress_graft,
 236         .leaf           =       ingress_leaf,
 237         .get            =       ingress_get,
 238         .put            =       ingress_put,
 239         .change         =       ingress_change,
 240         .walk           =       ingress_walk,
 241         .tcf_chain      =       ingress_find_tcf,
 242         .bind_tcf       =       ingress_bind_filter,
 243         .unbind_tcf     =       ingress_put,
 244 };
 245
 246 static struct Qdisc_ops ingress_qdisc_ops __read_mostly = {
 247         .cl_ops         =       &ingress_class_ops,
 248         .id             =       "ingress",
 249         .priv_size      =       sizeof(struct ingress_qdisc_data),
 250         .enqueue        =       ingress_enqueue,
 251         .dequeue        =       ingress_dequeue,
 252         .requeue        =       ingress_requeue,
 253         .drop           =       ingress_drop,
 254         .init           =       ingress_init,
 255         .reset          =       ingress_reset,
 256         .destroy        =       ingress_destroy,
 257         .dump           =       ingress_dump,
 258         .owner          =       THIS_MODULE,
 259 };
 260
 261 static int __init ingress_module_init(void)
 262 {
 263         int ret = 0;
 264
 265         if ((ret = register_qdisc(&ingress_qdisc_ops)) < 0) {
 266                 printk("Unable to register Ingress qdisc\n");
 267                 return ret;
 268         }
 269
 270         return ret;
 271 }
 272
 273 static void __exit ingress_module_exit(void)
 274 {
 275         unregister_qdisc(&ingress_qdisc_ops);
 276 #ifndef CONFIG_NET_CLS_ACT
 277 #ifdef CONFIG_NETFILTER
 278         if (nf_registered)
 279                 nf_unregister_hooks(ing_ops, ARRAY_SIZE(ing_ops));
 280 #endif
 281 #endif
 282 }
 283
 284 module_init(ingress_module_init)
 285 module_exit(ingress_module_exit)
 286 MODULE_LICENSE("GPL");