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