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_%d\n", 39 (char *)d->tcfd_defdata, d->tcf_bstats.packets); 40 spin_unlock(&d->tcf_lock); 41 return d->tcf_action; 42 } 43 44 static void tcf_simp_release(struct tc_action *a) 45 { 46 struct tcf_defact *d = to_defact(a); 47 kfree(d->tcfd_defdata); 48 } 49 50 static int alloc_defdata(struct tcf_defact *d, const struct nlattr *defdata) 51 { 52 d->tcfd_defdata = kzalloc(SIMP_MAX_DATA, GFP_KERNEL); 53 if (unlikely(!d->tcfd_defdata)) 54 return -ENOMEM; 55 nla_strlcpy(d->tcfd_defdata, defdata, SIMP_MAX_DATA); 56 return 0; 57 } 58 59 static int reset_policy(struct tc_action *a, const struct nlattr *defdata, 60 struct tc_defact *p, struct tcf_proto *tp, 61 struct netlink_ext_ack *extack) 62 { 63 struct tcf_chain *goto_ch = NULL; 64 struct tcf_defact *d; 65 int err; 66 67 err = tcf_action_check_ctrlact(p->action, tp, &goto_ch, extack); 68 if (err < 0) 69 return err; 70 d = to_defact(a); 71 spin_lock_bh(&d->tcf_lock); 72 goto_ch = tcf_action_set_ctrlact(a, p->action, goto_ch); 73 memset(d->tcfd_defdata, 0, SIMP_MAX_DATA); 74 nla_strlcpy(d->tcfd_defdata, defdata, SIMP_MAX_DATA); 75 spin_unlock_bh(&d->tcf_lock); 76 if (goto_ch) 77 tcf_chain_put_by_act(goto_ch); 78 return 0; 79 } 80 81 static const struct nla_policy simple_policy[TCA_DEF_MAX + 1] = { 82 [TCA_DEF_PARMS] = { .len = sizeof(struct tc_defact) }, 83 [TCA_DEF_DATA] = { .type = NLA_STRING, .len = SIMP_MAX_DATA }, 84 }; 85 86 static int tcf_simp_init(struct net *net, struct nlattr *nla, 87 struct nlattr *est, struct tc_action **a, 88 int ovr, int bind, bool rtnl_held, 89 struct tcf_proto *tp, struct netlink_ext_ack *extack) 90 { 91 struct tc_action_net *tn = net_generic(net, simp_net_id); 92 struct nlattr *tb[TCA_DEF_MAX + 1]; 93 struct tcf_chain *goto_ch = NULL; 94 struct tc_defact *parm; 95 struct tcf_defact *d; 96 bool exists = false; 97 int ret = 0, err; 98 99 if (nla == NULL) 100 return -EINVAL; 101 102 err = nla_parse_nested_deprecated(tb, TCA_DEF_MAX, nla, simple_policy, 103 NULL); 104 if (err < 0) 105 return err; 106 107 if (tb[TCA_DEF_PARMS] == NULL) 108 return -EINVAL; 109 110 parm = nla_data(tb[TCA_DEF_PARMS]); 111 err = tcf_idr_check_alloc(tn, &parm->index, a, bind); 112 if (err < 0) 113 return err; 114 exists = err; 115 if (exists && bind) 116 return 0; 117 118 if (tb[TCA_DEF_DATA] == NULL) { 119 if (exists) 120 tcf_idr_release(*a, bind); 121 else 122 tcf_idr_cleanup(tn, parm->index); 123 return -EINVAL; 124 } 125 126 if (!exists) { 127 ret = tcf_idr_create(tn, parm->index, est, a, 128 &act_simp_ops, bind, false); 129 if (ret) { 130 tcf_idr_cleanup(tn, parm->index); 131 return ret; 132 } 133 134 d = to_defact(*a); 135 err = tcf_action_check_ctrlact(parm->action, tp, &goto_ch, 136 extack); 137 if (err < 0) 138 goto release_idr; 139 140 err = alloc_defdata(d, tb[TCA_DEF_DATA]); 141 if (err < 0) 142 goto put_chain; 143 144 tcf_action_set_ctrlact(*a, parm->action, goto_ch); 145 ret = ACT_P_CREATED; 146 } else { 147 if (!ovr) { 148 err = -EEXIST; 149 goto release_idr; 150 } 151 152 err = reset_policy(*a, tb[TCA_DEF_DATA], parm, tp, extack); 153 if (err) 154 goto release_idr; 155 } 156 157 if (ret == ACT_P_CREATED) 158 tcf_idr_insert(tn, *a); 159 return ret; 160 put_chain: 161 if (goto_ch) 162 tcf_chain_put_by_act(goto_ch); 163 release_idr: 164 tcf_idr_release(*a, bind); 165 return err; 166 } 167 168 static int tcf_simp_dump(struct sk_buff *skb, struct tc_action *a, 169 int bind, int ref) 170 { 171 unsigned char *b = skb_tail_pointer(skb); 172 struct tcf_defact *d = to_defact(a); 173 struct tc_defact opt = { 174 .index = d->tcf_index, 175 .refcnt = refcount_read(&d->tcf_refcnt) - ref, 176 .bindcnt = atomic_read(&d->tcf_bindcnt) - bind, 177 }; 178 struct tcf_t t; 179 180 spin_lock_bh(&d->tcf_lock); 181 opt.action = d->tcf_action; 182 if (nla_put(skb, TCA_DEF_PARMS, sizeof(opt), &opt) || 183 nla_put_string(skb, TCA_DEF_DATA, d->tcfd_defdata)) 184 goto nla_put_failure; 185 186 tcf_tm_dump(&t, &d->tcf_tm); 187 if (nla_put_64bit(skb, TCA_DEF_TM, sizeof(t), &t, TCA_DEF_PAD)) 188 goto nla_put_failure; 189 spin_unlock_bh(&d->tcf_lock); 190 191 return skb->len; 192 193 nla_put_failure: 194 spin_unlock_bh(&d->tcf_lock); 195 nlmsg_trim(skb, b); 196 return -1; 197 } 198 199 static int tcf_simp_walker(struct net *net, struct sk_buff *skb, 200 struct netlink_callback *cb, int type, 201 const struct tc_action_ops *ops, 202 struct netlink_ext_ack *extack) 203 { 204 struct tc_action_net *tn = net_generic(net, simp_net_id); 205 206 return tcf_generic_walker(tn, skb, cb, type, ops, extack); 207 } 208 209 static int tcf_simp_search(struct net *net, struct tc_action **a, u32 index) 210 { 211 struct tc_action_net *tn = net_generic(net, simp_net_id); 212 213 return tcf_idr_search(tn, a, index); 214 } 215 216 static struct tc_action_ops act_simp_ops = { 217 .kind = "simple", 218 .id = TCA_ID_SIMP, 219 .owner = THIS_MODULE, 220 .act = tcf_simp_act, 221 .dump = tcf_simp_dump, 222 .cleanup = tcf_simp_release, 223 .init = tcf_simp_init, 224 .walk = tcf_simp_walker, 225 .lookup = tcf_simp_search, 226 .size = sizeof(struct tcf_defact), 227 }; 228 229 static __net_init int simp_init_net(struct net *net) 230 { 231 struct tc_action_net *tn = net_generic(net, simp_net_id); 232 233 return tc_action_net_init(tn, &act_simp_ops); 234 } 235 236 static void __net_exit simp_exit_net(struct list_head *net_list) 237 { 238 tc_action_net_exit(net_list, simp_net_id); 239 } 240 241 static struct pernet_operations simp_net_ops = { 242 .init = simp_init_net, 243 .exit_batch = simp_exit_net, 244 .id = &simp_net_id, 245 .size = sizeof(struct tc_action_net), 246 }; 247 248 MODULE_AUTHOR("Jamal Hadi Salim(2005)"); 249 MODULE_DESCRIPTION("Simple example action"); 250 MODULE_LICENSE("GPL"); 251 252 static int __init simp_init_module(void) 253 { 254 int ret = tcf_register_action(&act_simp_ops, &simp_net_ops); 255 if (!ret) 256 pr_info("Simple TC action Loaded\n"); 257 return ret; 258 } 259 260 static void __exit simp_cleanup_module(void) 261 { 262 tcf_unregister_action(&act_simp_ops, &simp_net_ops); 263 } 264 265 module_init(simp_init_module); 266 module_exit(simp_cleanup_module); 267