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 18 #include <linux/tc_act/tc_defact.h> 19 #include <net/tc_act/tc_defact.h> 20 21 static unsigned int simp_net_id; 22 static struct tc_action_ops act_simp_ops; 23 24 #define SIMP_MAX_DATA 32 25 static int tcf_simp_act(struct sk_buff *skb, const struct tc_action *a, 26 struct tcf_result *res) 27 { 28 struct tcf_defact *d = to_defact(a); 29 30 spin_lock(&d->tcf_lock); 31 tcf_lastuse_update(&d->tcf_tm); 32 bstats_update(&d->tcf_bstats, skb); 33 34 /* print policy string followed by _ then packet count 35 * Example if this was the 3rd packet and the string was "hello" 36 * then it would look like "hello_3" (without quotes) 37 */ 38 pr_info("simple: %s_%llu\n", 39 (char *)d->tcfd_defdata, 40 u64_stats_read(&d->tcf_bstats.packets)); 41 spin_unlock(&d->tcf_lock); 42 return d->tcf_action; 43 } 44 45 static void tcf_simp_release(struct tc_action *a) 46 { 47 struct tcf_defact *d = to_defact(a); 48 kfree(d->tcfd_defdata); 49 } 50 51 static int alloc_defdata(struct tcf_defact *d, const struct nlattr *defdata) 52 { 53 d->tcfd_defdata = kzalloc(SIMP_MAX_DATA, GFP_KERNEL); 54 if (unlikely(!d->tcfd_defdata)) 55 return -ENOMEM; 56 nla_strscpy(d->tcfd_defdata, defdata, SIMP_MAX_DATA); 57 return 0; 58 } 59 60 static int reset_policy(struct tc_action *a, const struct nlattr *defdata, 61 struct tc_defact *p, struct tcf_proto *tp, 62 struct netlink_ext_ack *extack) 63 { 64 struct tcf_chain *goto_ch = NULL; 65 struct tcf_defact *d; 66 int err; 67 68 err = tcf_action_check_ctrlact(p->action, tp, &goto_ch, extack); 69 if (err < 0) 70 return err; 71 d = to_defact(a); 72 spin_lock_bh(&d->tcf_lock); 73 goto_ch = tcf_action_set_ctrlact(a, p->action, goto_ch); 74 memset(d->tcfd_defdata, 0, SIMP_MAX_DATA); 75 nla_strscpy(d->tcfd_defdata, defdata, SIMP_MAX_DATA); 76 spin_unlock_bh(&d->tcf_lock); 77 if (goto_ch) 78 tcf_chain_put_by_act(goto_ch); 79 return 0; 80 } 81 82 static const struct nla_policy simple_policy[TCA_DEF_MAX + 1] = { 83 [TCA_DEF_PARMS] = { .len = sizeof(struct tc_defact) }, 84 [TCA_DEF_DATA] = { .type = NLA_STRING, .len = SIMP_MAX_DATA }, 85 }; 86 87 static int tcf_simp_init(struct net *net, struct nlattr *nla, 88 struct nlattr *est, struct tc_action **a, 89 struct tcf_proto *tp, u32 flags, 90 struct netlink_ext_ack *extack) 91 { 92 struct tc_action_net *tn = net_generic(net, simp_net_id); 93 bool bind = flags & TCA_ACT_FLAGS_BIND; 94 struct nlattr *tb[TCA_DEF_MAX + 1]; 95 struct tcf_chain *goto_ch = NULL; 96 struct tc_defact *parm; 97 struct tcf_defact *d; 98 bool exists = false; 99 int ret = 0, err; 100 u32 index; 101 102 if (nla == NULL) 103 return -EINVAL; 104 105 err = nla_parse_nested_deprecated(tb, TCA_DEF_MAX, nla, simple_policy, 106 NULL); 107 if (err < 0) 108 return err; 109 110 if (tb[TCA_DEF_PARMS] == NULL) 111 return -EINVAL; 112 113 parm = nla_data(tb[TCA_DEF_PARMS]); 114 index = parm->index; 115 err = tcf_idr_check_alloc(tn, &index, a, bind); 116 if (err < 0) 117 return err; 118 exists = err; 119 if (exists && bind) 120 return 0; 121 122 if (tb[TCA_DEF_DATA] == NULL) { 123 if (exists) 124 tcf_idr_release(*a, bind); 125 else 126 tcf_idr_cleanup(tn, index); 127 return -EINVAL; 128 } 129 130 if (!exists) { 131 ret = tcf_idr_create(tn, index, est, a, 132 &act_simp_ops, bind, false, 0); 133 if (ret) { 134 tcf_idr_cleanup(tn, index); 135 return ret; 136 } 137 138 d = to_defact(*a); 139 err = tcf_action_check_ctrlact(parm->action, tp, &goto_ch, 140 extack); 141 if (err < 0) 142 goto release_idr; 143 144 err = alloc_defdata(d, tb[TCA_DEF_DATA]); 145 if (err < 0) 146 goto put_chain; 147 148 tcf_action_set_ctrlact(*a, parm->action, goto_ch); 149 ret = ACT_P_CREATED; 150 } else { 151 if (!(flags & TCA_ACT_FLAGS_REPLACE)) { 152 err = -EEXIST; 153 goto release_idr; 154 } 155 156 err = reset_policy(*a, tb[TCA_DEF_DATA], parm, tp, extack); 157 if (err) 158 goto release_idr; 159 } 160 161 return ret; 162 put_chain: 163 if (goto_ch) 164 tcf_chain_put_by_act(goto_ch); 165 release_idr: 166 tcf_idr_release(*a, bind); 167 return err; 168 } 169 170 static int tcf_simp_dump(struct sk_buff *skb, struct tc_action *a, 171 int bind, int ref) 172 { 173 unsigned char *b = skb_tail_pointer(skb); 174 struct tcf_defact *d = to_defact(a); 175 struct tc_defact opt = { 176 .index = d->tcf_index, 177 .refcnt = refcount_read(&d->tcf_refcnt) - ref, 178 .bindcnt = atomic_read(&d->tcf_bindcnt) - bind, 179 }; 180 struct tcf_t t; 181 182 spin_lock_bh(&d->tcf_lock); 183 opt.action = d->tcf_action; 184 if (nla_put(skb, TCA_DEF_PARMS, sizeof(opt), &opt) || 185 nla_put_string(skb, TCA_DEF_DATA, d->tcfd_defdata)) 186 goto nla_put_failure; 187 188 tcf_tm_dump(&t, &d->tcf_tm); 189 if (nla_put_64bit(skb, TCA_DEF_TM, sizeof(t), &t, TCA_DEF_PAD)) 190 goto nla_put_failure; 191 spin_unlock_bh(&d->tcf_lock); 192 193 return skb->len; 194 195 nla_put_failure: 196 spin_unlock_bh(&d->tcf_lock); 197 nlmsg_trim(skb, b); 198 return -1; 199 } 200 201 static int tcf_simp_walker(struct net *net, struct sk_buff *skb, 202 struct netlink_callback *cb, int type, 203 const struct tc_action_ops *ops, 204 struct netlink_ext_ack *extack) 205 { 206 struct tc_action_net *tn = net_generic(net, simp_net_id); 207 208 return tcf_generic_walker(tn, skb, cb, type, ops, extack); 209 } 210 211 static int tcf_simp_search(struct net *net, struct tc_action **a, u32 index) 212 { 213 struct tc_action_net *tn = net_generic(net, simp_net_id); 214 215 return tcf_idr_search(tn, a, index); 216 } 217 218 static struct tc_action_ops act_simp_ops = { 219 .kind = "simple", 220 .id = TCA_ID_SIMP, 221 .owner = THIS_MODULE, 222 .act = tcf_simp_act, 223 .dump = tcf_simp_dump, 224 .cleanup = tcf_simp_release, 225 .init = tcf_simp_init, 226 .walk = tcf_simp_walker, 227 .lookup = tcf_simp_search, 228 .size = sizeof(struct tcf_defact), 229 }; 230 231 static __net_init int simp_init_net(struct net *net) 232 { 233 struct tc_action_net *tn = net_generic(net, simp_net_id); 234 235 return tc_action_net_init(net, tn, &act_simp_ops); 236 } 237 238 static void __net_exit simp_exit_net(struct list_head *net_list) 239 { 240 tc_action_net_exit(net_list, simp_net_id); 241 } 242 243 static struct pernet_operations simp_net_ops = { 244 .init = simp_init_net, 245 .exit_batch = simp_exit_net, 246 .id = &simp_net_id, 247 .size = sizeof(struct tc_action_net), 248 }; 249 250 MODULE_AUTHOR("Jamal Hadi Salim(2005)"); 251 MODULE_DESCRIPTION("Simple example action"); 252 MODULE_LICENSE("GPL"); 253 254 static int __init simp_init_module(void) 255 { 256 int ret = tcf_register_action(&act_simp_ops, &simp_net_ops); 257 if (!ret) 258 pr_info("Simple TC action Loaded\n"); 259 return ret; 260 } 261 262 static void __exit simp_cleanup_module(void) 263 { 264 tcf_unregister_action(&act_simp_ops, &simp_net_ops); 265 } 266 267 module_init(simp_init_module); 268 module_exit(simp_cleanup_module); 269