net/sched/sch_ingress.c

   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 <net/netlink.h>
  16 #include <net/pkt_sched.h>
  17
  18
  19 struct ingress_qdisc_data {
  20         struct tcf_proto        *filter_list;
  21 };
  22
  23 /* ------------------------- Class/flow operations ------------------------- */
  24
  25 static struct Qdisc *ingress_leaf(struct Qdisc *sch, unsigned long arg)
  26 {
  27         return NULL;
  28 }
  29
  30 static unsigned long ingress_get(struct Qdisc *sch, u32 classid)
  31 {
  32         return TC_H_MIN(classid) + 1;
  33 }
  34
  35 static unsigned long ingress_bind_filter(struct Qdisc *sch,
  36                                          unsigned long parent, u32 classid)
  37 {
  38         return ingress_get(sch, classid);
  39 }
  40
  41 static void ingress_put(struct Qdisc *sch, unsigned long cl)
  42 {
  43 }
  44
  45 static void ingress_walk(struct Qdisc *sch, struct qdisc_walker *walker)
  46 {
  47 }
  48
  49 static struct tcf_proto **ingress_find_tcf(struct Qdisc *sch, unsigned long cl)
  50 {
  51         struct ingress_qdisc_data *p = qdisc_priv(sch);
  52
  53         return &p->filter_list;
  54 }
  55
  56 /* --------------------------- Qdisc operations ---------------------------- */
  57
  58 static int ingress_enqueue(struct sk_buff *skb, struct Qdisc *sch)
  59 {
  60         struct ingress_qdisc_data *p = qdisc_priv(sch);
  61         struct tcf_result res;
  62         int result;
  63
  64         result = tc_classify(skb, p->filter_list, &res);
  65
  66         qdisc_bstats_update(sch, skb);
  67         switch (result) {
  68         case TC_ACT_SHOT:
  69                 result = TC_ACT_SHOT;
  70                 sch->qstats.drops++;
  71                 break;
  72         case TC_ACT_STOLEN:
  73         case TC_ACT_QUEUED:
  74                 result = TC_ACT_STOLEN;
  75                 break;
  76         case TC_ACT_RECLASSIFY:
  77         case TC_ACT_OK:
  78                 skb->tc_index = TC_H_MIN(res.classid);
  79         default:
  80                 result = TC_ACT_OK;
  81                 break;
  82         }
  83
  84         return result;
  85 }
  86
  87 /* ------------------------------------------------------------- */
  88
  89 static void ingress_destroy(struct Qdisc *sch)
  90 {
  91         struct ingress_qdisc_data *p = qdisc_priv(sch);
  92
  93         tcf_destroy_chain(&p->filter_list);
  94 }
  95
  96 static int ingress_dump(struct Qdisc *sch, struct sk_buff *skb)
  97 {
  98         struct nlattr *nest;
  99
 100         nest = nla_nest_start(skb, TCA_OPTIONS);
 101         if (nest == NULL)
 102                 goto nla_put_failure;
 103         nla_nest_end(skb, nest);
 104         return skb->len;
 105
 106 nla_put_failure:
 107         nla_nest_cancel(skb, nest);
 108         return -1;
 109 }
 110
 111 static const struct Qdisc_class_ops ingress_class_ops = {
 112         .leaf           =       ingress_leaf,
 113         .get            =       ingress_get,
 114         .put            =       ingress_put,
 115         .walk           =       ingress_walk,
 116         .tcf_chain      =       ingress_find_tcf,
 117         .bind_tcf       =       ingress_bind_filter,
 118         .unbind_tcf     =       ingress_put,
 119 };
 120
 121 static struct Qdisc_ops ingress_qdisc_ops __read_mostly = {
 122         .cl_ops         =       &ingress_class_ops,
 123         .id             =       "ingress",
 124         .priv_size      =       sizeof(struct ingress_qdisc_data),
 125         .enqueue        =       ingress_enqueue,
 126         .destroy        =       ingress_destroy,
 127         .dump           =       ingress_dump,
 128         .owner          =       THIS_MODULE,
 129 };
 130
 131 static int __init ingress_module_init(void)
 132 {
 133         return register_qdisc(&ingress_qdisc_ops);
 134 }
 135
 136 static void __exit ingress_module_exit(void)
 137 {
 138         unregister_qdisc(&ingress_qdisc_ops);
 139 }
 140
 141 module_init(ingress_module_init)
 142 module_exit(ingress_module_exit)
 143 MODULE_LICENSE("GPL");