1 // SPDX-License-Identifier: GPL-2.0-or-later 2 /* 3 * net/sched/act_simple.c Simple example of an action 4 * 5 * Authors: Jamal Hadi Salim (2005-8) 6 */ 7 8 #include <linux/module.h> 9 #include <linux/slab.h> 10 #include <linux/init.h> 11 #include <linux/kernel.h> 12 #include <linux/skbuff.h> 13 #include <linux/rtnetlink.h> 14 #include <net/netlink.h> 15 #include <net/pkt_sched.h> 16 #include <net/pkt_cls.h> 17 #include <net/tc_wrapper.h> 18 19 #include <linux/tc_act/tc_defact.h> 20 #include <net/tc_act/tc_defact.h> 21 22 static struct tc_action_ops act_simp_ops; 23 24 #define SIMP_MAX_DATA 32 25 TC_INDIRECT_SCOPE int tcf_simp_act(struct sk_buff *skb, 26 const struct tc_action *a, 27 struct tcf_result *res) 28 { 29 struct tcf_defact *d = to_defact(a); 30 31 spin_lock(&d->tcf_lock); 32 tcf_lastuse_update(&d->tcf_tm); 33 bstats_update(&d->tcf_bstats, skb); 34 35 /* print policy string followed by _ then packet count 36 * Example if this was the 3rd packet and the string was "hello" 37 * then it would look like "hello_3" (without quotes) 38 */ 39 pr_info("simple: %s_%llu\n", 40 (char *)d->tcfd_defdata, 41 u64_stats_read(&d->tcf_bstats.packets)); 42 spin_unlock(&d->tcf_lock); 43 return d->tcf_action; 44 } 45 46 static void tcf_simp_release(struct tc_action *a) 47 { 48 struct tcf_defact *d = to_defact(a); 49 kfree(d->tcfd_defdata); 50 } 51 52 static int alloc_defdata(struct tcf_defact *d, const struct nlattr *defdata) 53 { 54 d->tcfd_defdata = kzalloc(SIMP_MAX_DATA, GFP_KERNEL); 55 if (unlikely(!d->tcfd_defdata)) 56 return -ENOMEM; 57 nla_strscpy(d->tcfd_defdata, defdata, SIMP_MAX_DATA); 58 return 0; 59 } 60 61 static int reset_policy(struct tc_action *a, const struct nlattr *defdata, 62 struct tc_defact *p, struct tcf_proto *tp, 63 struct netlink_ext_ack *extack) 64 { 65 struct tcf_chain *goto_ch = NULL; 66 struct tcf_defact *d; 67 int err; 68 69 err = tcf_action_check_ctrlact(p->action, tp, &goto_ch, extack); 70 if (err < 0) 71 return err; 72 d = to_defact(a); 73 spin_lock_bh(&d->tcf_lock); 74 goto_ch = tcf_action_set_ctrlact(a, p->action, goto_ch); 75 memset(d->tcfd_defdata, 0, SIMP_MAX_DATA); 76 nla_strscpy(d->tcfd_defdata, defdata, SIMP_MAX_DATA); 77 spin_unlock_bh(&d->tcf_lock); 78 if (goto_ch) 79 tcf_chain_put_by_act(goto_ch); 80 return 0; 81 } 82 83 static const struct nla_policy simple_policy[TCA_DEF_MAX + 1] = { 84 [TCA_DEF_PARMS] = { .len = sizeof(struct tc_defact) }, 85 [TCA_DEF_DATA] = { .type = NLA_STRING, .len = SIMP_MAX_DATA }, 86 }; 87 88 static int tcf_simp_init(struct net *net, struct nlattr *nla, 89 struct nlattr *est, struct tc_action **a, 90 struct tcf_proto *tp, u32 flags, 91 struct netlink_ext_ack *extack) 92 { 93 struct tc_action_net *tn = net_generic(net, act_simp_ops.net_id); 94 bool bind = flags & TCA_ACT_FLAGS_BIND; 95 struct nlattr *tb[TCA_DEF_MAX + 1]; 96 struct tcf_chain *goto_ch = NULL; 97 struct tc_defact *parm; 98 struct tcf_defact *d; 99 bool exists = false; 100 int ret = 0, err; 101 u32 index; 102 103 if (nla == NULL) 104 return -EINVAL; 105 106 err = nla_parse_nested_deprecated(tb, TCA_DEF_MAX, nla, simple_policy, 107 NULL); 108 if (err < 0) 109 return err; 110 111 if (tb[TCA_DEF_PARMS] == NULL) 112 return -EINVAL; 113 114 parm = nla_data(tb[TCA_DEF_PARMS]); 115 index = parm->index; 116 err = tcf_idr_check_alloc(tn, &index, a, bind); 117 if (err < 0) 118 return err; 119 exists = err; 120 if (exists && bind) 121 return 0; 122 123 if (tb[TCA_DEF_DATA] == NULL) { 124 if (exists) 125 tcf_idr_release(*a, bind); 126 else 127 tcf_idr_cleanup(tn, index); 128 return -EINVAL; 129 } 130 131 if (!exists) { 132 ret = tcf_idr_create(tn, index, est, a, 133 &act_simp_ops, bind, false, flags); 134 if (ret) { 135 tcf_idr_cleanup(tn, index); 136 return ret; 137 } 138 139 d = to_defact(*a); 140 err = tcf_action_check_ctrlact(parm->action, tp, &goto_ch, 141 extack); 142 if (err < 0) 143 goto release_idr; 144 145 err = alloc_defdata(d, tb[TCA_DEF_DATA]); 146 if (err < 0) 147 goto put_chain; 148 149 tcf_action_set_ctrlact(*a, parm->action, goto_ch); 150 ret = ACT_P_CREATED; 151 } else { 152 if (!(flags & TCA_ACT_FLAGS_REPLACE)) { 153 err = -EEXIST; 154 goto release_idr; 155 } 156 157 err = reset_policy(*a, tb[TCA_DEF_DATA], parm, tp, extack); 158 if (err) 159 goto release_idr; 160 } 161 162 return ret; 163 put_chain: 164 if (goto_ch) 165 tcf_chain_put_by_act(goto_ch); 166 release_idr: 167 tcf_idr_release(*a, bind); 168 return err; 169 } 170 171 static int tcf_simp_dump(struct sk_buff *skb, struct tc_action *a, 172 int bind, int ref) 173 { 174 unsigned char *b = skb_tail_pointer(skb); 175 struct tcf_defact *d = to_defact(a); 176 struct tc_defact opt = { 177 .index = d->tcf_index, 178 .refcnt = refcount_read(&d->tcf_refcnt) - ref, 179 .bindcnt = atomic_read(&d->tcf_bindcnt) - bind, 180 }; 181 struct tcf_t t; 182 183 spin_lock_bh(&d->tcf_lock); 184 opt.action = d->tcf_action; 185 if (nla_put(skb, TCA_DEF_PARMS, sizeof(opt), &opt) || 186 nla_put_string(skb, TCA_DEF_DATA, d->tcfd_defdata)) 187 goto nla_put_failure; 188 189 tcf_tm_dump(&t, &d->tcf_tm); 190 if (nla_put_64bit(skb, TCA_DEF_TM, sizeof(t), &t, TCA_DEF_PAD)) 191 goto nla_put_failure; 192 spin_unlock_bh(&d->tcf_lock); 193 194 return skb->len; 195 196 nla_put_failure: 197 spin_unlock_bh(&d->tcf_lock); 198 nlmsg_trim(skb, b); 199 return -1; 200 } 201 202 static struct tc_action_ops act_simp_ops = { 203 .kind = "simple", 204 .id = TCA_ID_SIMP, 205 .owner = THIS_MODULE, 206 .act = tcf_simp_act, 207 .dump = tcf_simp_dump, 208 .cleanup = tcf_simp_release, 209 .init = tcf_simp_init, 210 .size = sizeof(struct tcf_defact), 211 }; 212 213 static __net_init int simp_init_net(struct net *net) 214 { 215 struct tc_action_net *tn = net_generic(net, act_simp_ops.net_id); 216 217 return tc_action_net_init(net, tn, &act_simp_ops); 218 } 219 220 static void __net_exit simp_exit_net(struct list_head *net_list) 221 { 222 tc_action_net_exit(net_list, act_simp_ops.net_id); 223 } 224 225 static struct pernet_operations simp_net_ops = { 226 .init = simp_init_net, 227 .exit_batch = simp_exit_net, 228 .id = &act_simp_ops.net_id, 229 .size = sizeof(struct tc_action_net), 230 }; 231 232 MODULE_AUTHOR("Jamal Hadi Salim(2005)"); 233 MODULE_DESCRIPTION("Simple example action"); 234 MODULE_LICENSE("GPL"); 235 236 static int __init simp_init_module(void) 237 { 238 int ret = tcf_register_action(&act_simp_ops, &simp_net_ops); 239 if (!ret) 240 pr_info("Simple TC action Loaded\n"); 241 return ret; 242 } 243 244 static void __exit simp_cleanup_module(void) 245 { 246 tcf_unregister_action(&act_simp_ops, &simp_net_ops); 247 } 248 249 module_init(simp_init_module); 250 module_exit(simp_cleanup_module); 251