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 int ingress_graft(struct Qdisc *sch, unsigned long arg,
  26                          struct Qdisc *new, struct Qdisc **old)
  27 {
  28         return -EOPNOTSUPP;
  29 }
  30
  31 static struct Qdisc *ingress_leaf(struct Qdisc *sch, unsigned long arg)
  32 {
  33         return NULL;
  34 }
  35
  36 static unsigned long ingress_get(struct Qdisc *sch, u32 classid)
  37 {
  38         return TC_H_MIN(classid) + 1;
  39 }
  40
  41 static unsigned long ingress_bind_filter(struct Qdisc *sch,
  42                                          unsigned long parent, u32 classid)
  43 {
  44         return ingress_get(sch, classid);
  45 }
  46
  47 static void ingress_put(struct Qdisc *sch, unsigned long cl)
  48 {
  49 }
  50
  51 static int ingress_change(struct Qdisc *sch, u32 classid, u32 parent,
  52                           struct nlattr **tca, unsigned long *arg)
  53 {
  54         return 0;
  55 }
  56
  57 static void ingress_walk(struct Qdisc *sch, struct qdisc_walker *walker)
  58 {
  59         return;
  60 }
  61
  62 static struct tcf_proto **ingress_find_tcf(struct Qdisc *sch, unsigned long cl)
  63 {
  64         struct ingress_qdisc_data *p = qdisc_priv(sch);
  65
  66         return &p->filter_list;
  67 }
  68
  69 /* --------------------------- Qdisc operations ---------------------------- */
  70
  71 static int ingress_enqueue(struct sk_buff *skb, struct Qdisc *sch)
  72 {
  73         struct ingress_qdisc_data *p = qdisc_priv(sch);
  74         struct tcf_result res;
  75         int result;
  76
  77         result = tc_classify(skb, p->filter_list, &res);
  78
  79         sch->bstats.packets++;
  80         sch->bstats.bytes += qdisc_pkt_len(skb);
  81         switch (result) {
  82         case TC_ACT_SHOT:
  83                 result = TC_ACT_SHOT;
  84                 sch->qstats.drops++;
  85                 break;
  86         case TC_ACT_STOLEN:
  87         case TC_ACT_QUEUED:
  88                 result = TC_ACT_STOLEN;
  89                 break;
  90         case TC_ACT_RECLASSIFY:
  91         case TC_ACT_OK:
  92                 skb->tc_index = TC_H_MIN(res.classid);
  93         default:
  94                 result = TC_ACT_OK;
  95                 break;
  96         }
  97
  98         return result;
  99 }
 100
 101 /* ------------------------------------------------------------- */
 102
 103 static void ingress_destroy(struct Qdisc *sch)
 104 {
 105         struct ingress_qdisc_data *p = qdisc_priv(sch);
 106
 107         tcf_destroy_chain(&p->filter_list);
 108 }
 109
 110 static int ingress_dump(struct Qdisc *sch, struct sk_buff *skb)
 111 {
 112         struct nlattr *nest;
 113
 114         nest = nla_nest_start(skb, TCA_OPTIONS);
 115         if (nest == NULL)
 116                 goto nla_put_failure;
 117         nla_nest_end(skb, nest);
 118         return skb->len;
 119
 120 nla_put_failure:
 121         nla_nest_cancel(skb, nest);
 122         return -1;
 123 }
 124
 125 static const struct Qdisc_class_ops ingress_class_ops = {
 126         .graft          =       ingress_graft,
 127         .leaf           =       ingress_leaf,
 128         .get            =       ingress_get,
 129         .put            =       ingress_put,
 130         .change         =       ingress_change,
 131         .walk           =       ingress_walk,
 132         .tcf_chain      =       ingress_find_tcf,
 133         .bind_tcf       =       ingress_bind_filter,
 134         .unbind_tcf     =       ingress_put,
 135 };
 136
 137 static struct Qdisc_ops ingress_qdisc_ops __read_mostly = {
 138         .cl_ops         =       &ingress_class_ops,
 139         .id             =       "ingress",
 140         .priv_size      =       sizeof(struct ingress_qdisc_data),
 141         .enqueue        =       ingress_enqueue,
 142         .destroy        =       ingress_destroy,
 143         .dump           =       ingress_dump,
 144         .owner          =       THIS_MODULE,
 145 };
 146
 147 static int __init ingress_module_init(void)
 148 {
 149         return register_qdisc(&ingress_qdisc_ops);
 150 }
 151
 152 static void __exit ingress_module_exit(void)
 153 {
 154         unregister_qdisc(&ingress_qdisc_ops);
 155 }
 156
 157 module_init(ingress_module_init)
 158 module_exit(ingress_module_exit)
 159 MODULE_LICENSE("GPL");