1 /* 2 * net/sched/cls_cgroup.c Control Group Classifier 3 * 4 * This program is free software; you can redistribute it and/or 5 * modify it under the terms of the GNU General Public License 6 * as published by the Free Software Foundation; either version 7 * 2 of the License, or (at your option) any later version. 8 * 9 * Authors: Thomas Graf <tgraf@suug.ch> 10 */ 11 12 #include <linux/module.h> 13 #include <linux/slab.h> 14 #include <linux/skbuff.h> 15 #include <linux/rcupdate.h> 16 #include <net/rtnetlink.h> 17 #include <net/pkt_cls.h> 18 #include <net/sock.h> 19 #include <net/cls_cgroup.h> 20 21 struct cls_cgroup_head { 22 u32 handle; 23 struct tcf_exts exts; 24 struct tcf_ematch_tree ematches; 25 struct tcf_proto *tp; 26 struct rcu_head rcu; 27 }; 28 29 static int cls_cgroup_classify(struct sk_buff *skb, const struct tcf_proto *tp, 30 struct tcf_result *res) 31 { 32 struct cls_cgroup_head *head = rcu_dereference_bh(tp->root); 33 u32 classid = task_get_classid(skb); 34 35 if (!classid) 36 return -1; 37 if (!tcf_em_tree_match(skb, &head->ematches, NULL)) 38 return -1; 39 40 res->classid = classid; 41 res->class = 0; 42 43 return tcf_exts_exec(skb, &head->exts, res); 44 } 45 46 static unsigned long cls_cgroup_get(struct tcf_proto *tp, u32 handle) 47 { 48 return 0UL; 49 } 50 51 static int cls_cgroup_init(struct tcf_proto *tp) 52 { 53 return 0; 54 } 55 56 static const struct nla_policy cgroup_policy[TCA_CGROUP_MAX + 1] = { 57 [TCA_CGROUP_EMATCHES] = { .type = NLA_NESTED }, 58 }; 59 60 static void cls_cgroup_destroy_rcu(struct rcu_head *root) 61 { 62 struct cls_cgroup_head *head = container_of(root, 63 struct cls_cgroup_head, 64 rcu); 65 66 tcf_exts_destroy(&head->exts); 67 tcf_em_tree_destroy(&head->ematches); 68 kfree(head); 69 } 70 71 static int cls_cgroup_change(struct net *net, struct sk_buff *in_skb, 72 struct tcf_proto *tp, unsigned long base, 73 u32 handle, struct nlattr **tca, 74 unsigned long *arg, bool ovr) 75 { 76 struct nlattr *tb[TCA_CGROUP_MAX + 1]; 77 struct cls_cgroup_head *head = rtnl_dereference(tp->root); 78 struct cls_cgroup_head *new; 79 struct tcf_ematch_tree t; 80 struct tcf_exts e; 81 int err; 82 83 if (!tca[TCA_OPTIONS]) 84 return -EINVAL; 85 86 if (!head && !handle) 87 return -EINVAL; 88 89 if (head && handle != head->handle) 90 return -ENOENT; 91 92 new = kzalloc(sizeof(*head), GFP_KERNEL); 93 if (!new) 94 return -ENOBUFS; 95 96 tcf_exts_init(&new->exts, TCA_CGROUP_ACT, TCA_CGROUP_POLICE); 97 new->handle = handle; 98 new->tp = tp; 99 err = nla_parse_nested(tb, TCA_CGROUP_MAX, tca[TCA_OPTIONS], 100 cgroup_policy); 101 if (err < 0) 102 goto errout; 103 104 tcf_exts_init(&e, TCA_CGROUP_ACT, TCA_CGROUP_POLICE); 105 err = tcf_exts_validate(net, tp, tb, tca[TCA_RATE], &e, ovr); 106 if (err < 0) 107 goto errout; 108 109 err = tcf_em_tree_validate(tp, tb[TCA_CGROUP_EMATCHES], &t); 110 if (err < 0) { 111 tcf_exts_destroy(&e); 112 goto errout; 113 } 114 115 tcf_exts_change(tp, &new->exts, &e); 116 tcf_em_tree_change(tp, &new->ematches, &t); 117 118 rcu_assign_pointer(tp->root, new); 119 if (head) 120 call_rcu(&head->rcu, cls_cgroup_destroy_rcu); 121 return 0; 122 errout: 123 kfree(new); 124 return err; 125 } 126 127 static bool cls_cgroup_destroy(struct tcf_proto *tp, bool force) 128 { 129 struct cls_cgroup_head *head = rtnl_dereference(tp->root); 130 131 if (!force) 132 return false; 133 134 if (head) { 135 RCU_INIT_POINTER(tp->root, NULL); 136 call_rcu(&head->rcu, cls_cgroup_destroy_rcu); 137 } 138 return true; 139 } 140 141 static int cls_cgroup_delete(struct tcf_proto *tp, unsigned long arg) 142 { 143 return -EOPNOTSUPP; 144 } 145 146 static void cls_cgroup_walk(struct tcf_proto *tp, struct tcf_walker *arg) 147 { 148 struct cls_cgroup_head *head = rtnl_dereference(tp->root); 149 150 if (arg->count < arg->skip) 151 goto skip; 152 153 if (arg->fn(tp, (unsigned long) head, arg) < 0) { 154 arg->stop = 1; 155 return; 156 } 157 skip: 158 arg->count++; 159 } 160 161 static int cls_cgroup_dump(struct net *net, struct tcf_proto *tp, unsigned long fh, 162 struct sk_buff *skb, struct tcmsg *t) 163 { 164 struct cls_cgroup_head *head = rtnl_dereference(tp->root); 165 struct nlattr *nest; 166 167 t->tcm_handle = head->handle; 168 169 nest = nla_nest_start(skb, TCA_OPTIONS); 170 if (nest == NULL) 171 goto nla_put_failure; 172 173 if (tcf_exts_dump(skb, &head->exts) < 0 || 174 tcf_em_tree_dump(skb, &head->ematches, TCA_CGROUP_EMATCHES) < 0) 175 goto nla_put_failure; 176 177 nla_nest_end(skb, nest); 178 179 if (tcf_exts_dump_stats(skb, &head->exts) < 0) 180 goto nla_put_failure; 181 182 return skb->len; 183 184 nla_put_failure: 185 nla_nest_cancel(skb, nest); 186 return -1; 187 } 188 189 static struct tcf_proto_ops cls_cgroup_ops __read_mostly = { 190 .kind = "cgroup", 191 .init = cls_cgroup_init, 192 .change = cls_cgroup_change, 193 .classify = cls_cgroup_classify, 194 .destroy = cls_cgroup_destroy, 195 .get = cls_cgroup_get, 196 .delete = cls_cgroup_delete, 197 .walk = cls_cgroup_walk, 198 .dump = cls_cgroup_dump, 199 .owner = THIS_MODULE, 200 }; 201 202 static int __init init_cgroup_cls(void) 203 { 204 return register_tcf_proto_ops(&cls_cgroup_ops); 205 } 206 207 static void __exit exit_cgroup_cls(void) 208 { 209 unregister_tcf_proto_ops(&cls_cgroup_ops); 210 } 211 212 module_init(init_cgroup_cls); 213 module_exit(exit_cgroup_cls); 214 MODULE_LICENSE("GPL"); 215