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 __rcu  *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 __rcu **ingress_find_tcf(struct Qdisc *sch,
  50                                                  unsigned long cl)
  51 {
  52         struct ingress_qdisc_data *p = qdisc_priv(sch);
  53
  54         return &p->filter_list;
  55 }
  56
  57 /* --------------------------- Qdisc operations ---------------------------- */
  58
  59 static int ingress_enqueue(struct sk_buff *skb, struct Qdisc *sch)
  60 {
  61         struct ingress_qdisc_data *p = qdisc_priv(sch);
  62         struct tcf_result res;
  63         struct tcf_proto *fl = rcu_dereference_bh(p->filter_list);
  64         int result;
  65
  66         result = tc_classify(skb, fl, &res);
  67
  68         qdisc_bstats_update_cpu(sch, skb);
  69         switch (result) {
  70         case TC_ACT_SHOT:
  71                 result = TC_ACT_SHOT;
  72                 qdisc_qstats_drop_cpu(sch);
  73                 break;
  74         case TC_ACT_STOLEN:
  75         case TC_ACT_QUEUED:
  76                 result = TC_ACT_STOLEN;
  77                 break;
  78         case TC_ACT_RECLASSIFY:
  79         case TC_ACT_OK:
  80                 skb->tc_index = TC_H_MIN(res.classid);
  81         default:
  82                 result = TC_ACT_OK;
  83                 break;
  84         }
  85
  86         return result;
  87 }
  88
  89 /* ------------------------------------------------------------- */
  90
  91 static int ingress_init(struct Qdisc *sch, struct nlattr *opt)
  92 {
  93         net_inc_ingress_queue();
  94         sch->flags |= TCQ_F_CPUSTATS;
  95
  96         return 0;
  97 }
  98
  99 static void ingress_destroy(struct Qdisc *sch)
 100 {
 101         struct ingress_qdisc_data *p = qdisc_priv(sch);
 102
 103         tcf_destroy_chain(&p->filter_list);
 104         net_dec_ingress_queue();
 105 }
 106
 107 static int ingress_dump(struct Qdisc *sch, struct sk_buff *skb)
 108 {
 109         struct nlattr *nest;
 110
 111         nest = nla_nest_start(skb, TCA_OPTIONS);
 112         if (nest == NULL)
 113                 goto nla_put_failure;
 114         return nla_nest_end(skb, nest);
 115
 116 nla_put_failure:
 117         nla_nest_cancel(skb, nest);
 118         return -1;
 119 }
 120
 121 static const struct Qdisc_class_ops ingress_class_ops = {
 122         .leaf           =       ingress_leaf,
 123         .get            =       ingress_get,
 124         .put            =       ingress_put,
 125         .walk           =       ingress_walk,
 126         .tcf_chain      =       ingress_find_tcf,
 127         .bind_tcf       =       ingress_bind_filter,
 128         .unbind_tcf     =       ingress_put,
 129 };
 130
 131 static struct Qdisc_ops ingress_qdisc_ops __read_mostly = {
 132         .cl_ops         =       &ingress_class_ops,
 133         .id             =       "ingress",
 134         .priv_size      =       sizeof(struct ingress_qdisc_data),
 135         .enqueue        =       ingress_enqueue,
 136         .init           =       ingress_init,
 137         .destroy        =       ingress_destroy,
 138         .dump           =       ingress_dump,
 139         .owner          =       THIS_MODULE,
 140 };
 141
 142 static int __init ingress_module_init(void)
 143 {
 144         return register_qdisc(&ingress_qdisc_ops);
 145 }
 146
 147 static void __exit ingress_module_exit(void)
 148 {
 149         unregister_qdisc(&ingress_qdisc_ops);
 150 }
 151
 152 module_init(ingress_module_init)
 153 module_exit(ingress_module_exit)
 154 MODULE_LICENSE("GPL");