1 // SPDX-License-Identifier: GPL-2.0-only 2 /* 3 * Copyright (c) 2008, Intel Corporation. 4 * 5 * Author: Alexander Duyck <alexander.h.duyck@intel.com> 6 */ 7 8 #include <linux/module.h> 9 #include <linux/init.h> 10 #include <linux/kernel.h> 11 #include <linux/skbuff.h> 12 #include <linux/rtnetlink.h> 13 #include <net/netlink.h> 14 #include <net/pkt_sched.h> 15 #include <net/ip.h> 16 #include <net/ipv6.h> 17 #include <net/dsfield.h> 18 #include <net/pkt_cls.h> 19 20 #include <linux/tc_act/tc_skbedit.h> 21 #include <net/tc_act/tc_skbedit.h> 22 23 static unsigned int skbedit_net_id; 24 static struct tc_action_ops act_skbedit_ops; 25 26 static int tcf_skbedit_act(struct sk_buff *skb, const struct tc_action *a, 27 struct tcf_result *res) 28 { 29 struct tcf_skbedit *d = to_skbedit(a); 30 struct tcf_skbedit_params *params; 31 int action; 32 33 tcf_lastuse_update(&d->tcf_tm); 34 bstats_cpu_update(this_cpu_ptr(d->common.cpu_bstats), skb); 35 36 params = rcu_dereference_bh(d->params); 37 action = READ_ONCE(d->tcf_action); 38 39 if (params->flags & SKBEDIT_F_PRIORITY) 40 skb->priority = params->priority; 41 if (params->flags & SKBEDIT_F_INHERITDSFIELD) { 42 int wlen = skb_network_offset(skb); 43 44 switch (tc_skb_protocol(skb)) { 45 case htons(ETH_P_IP): 46 wlen += sizeof(struct iphdr); 47 if (!pskb_may_pull(skb, wlen)) 48 goto err; 49 skb->priority = ipv4_get_dsfield(ip_hdr(skb)) >> 2; 50 break; 51 52 case htons(ETH_P_IPV6): 53 wlen += sizeof(struct ipv6hdr); 54 if (!pskb_may_pull(skb, wlen)) 55 goto err; 56 skb->priority = ipv6_get_dsfield(ipv6_hdr(skb)) >> 2; 57 break; 58 } 59 } 60 if (params->flags & SKBEDIT_F_QUEUE_MAPPING && 61 skb->dev->real_num_tx_queues > params->queue_mapping) 62 skb_set_queue_mapping(skb, params->queue_mapping); 63 if (params->flags & SKBEDIT_F_MARK) { 64 skb->mark &= ~params->mask; 65 skb->mark |= params->mark & params->mask; 66 } 67 if (params->flags & SKBEDIT_F_PTYPE) 68 skb->pkt_type = params->ptype; 69 return action; 70 71 err: 72 qstats_drop_inc(this_cpu_ptr(d->common.cpu_qstats)); 73 return TC_ACT_SHOT; 74 } 75 76 static const struct nla_policy skbedit_policy[TCA_SKBEDIT_MAX + 1] = { 77 [TCA_SKBEDIT_PARMS] = { .len = sizeof(struct tc_skbedit) }, 78 [TCA_SKBEDIT_PRIORITY] = { .len = sizeof(u32) }, 79 [TCA_SKBEDIT_QUEUE_MAPPING] = { .len = sizeof(u16) }, 80 [TCA_SKBEDIT_MARK] = { .len = sizeof(u32) }, 81 [TCA_SKBEDIT_PTYPE] = { .len = sizeof(u16) }, 82 [TCA_SKBEDIT_MASK] = { .len = sizeof(u32) }, 83 [TCA_SKBEDIT_FLAGS] = { .len = sizeof(u64) }, 84 }; 85 86 static int tcf_skbedit_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, 90 struct netlink_ext_ack *extack) 91 { 92 struct tc_action_net *tn = net_generic(net, skbedit_net_id); 93 struct tcf_skbedit_params *params_new; 94 struct nlattr *tb[TCA_SKBEDIT_MAX + 1]; 95 struct tcf_chain *goto_ch = NULL; 96 struct tc_skbedit *parm; 97 struct tcf_skbedit *d; 98 u32 flags = 0, *priority = NULL, *mark = NULL, *mask = NULL; 99 u16 *queue_mapping = NULL, *ptype = NULL; 100 bool exists = false; 101 int ret = 0, err; 102 103 if (nla == NULL) 104 return -EINVAL; 105 106 err = nla_parse_nested_deprecated(tb, TCA_SKBEDIT_MAX, nla, 107 skbedit_policy, NULL); 108 if (err < 0) 109 return err; 110 111 if (tb[TCA_SKBEDIT_PARMS] == NULL) 112 return -EINVAL; 113 114 if (tb[TCA_SKBEDIT_PRIORITY] != NULL) { 115 flags |= SKBEDIT_F_PRIORITY; 116 priority = nla_data(tb[TCA_SKBEDIT_PRIORITY]); 117 } 118 119 if (tb[TCA_SKBEDIT_QUEUE_MAPPING] != NULL) { 120 flags |= SKBEDIT_F_QUEUE_MAPPING; 121 queue_mapping = nla_data(tb[TCA_SKBEDIT_QUEUE_MAPPING]); 122 } 123 124 if (tb[TCA_SKBEDIT_PTYPE] != NULL) { 125 ptype = nla_data(tb[TCA_SKBEDIT_PTYPE]); 126 if (!skb_pkt_type_ok(*ptype)) 127 return -EINVAL; 128 flags |= SKBEDIT_F_PTYPE; 129 } 130 131 if (tb[TCA_SKBEDIT_MARK] != NULL) { 132 flags |= SKBEDIT_F_MARK; 133 mark = nla_data(tb[TCA_SKBEDIT_MARK]); 134 } 135 136 if (tb[TCA_SKBEDIT_MASK] != NULL) { 137 flags |= SKBEDIT_F_MASK; 138 mask = nla_data(tb[TCA_SKBEDIT_MASK]); 139 } 140 141 if (tb[TCA_SKBEDIT_FLAGS] != NULL) { 142 u64 *pure_flags = nla_data(tb[TCA_SKBEDIT_FLAGS]); 143 144 if (*pure_flags & SKBEDIT_F_INHERITDSFIELD) 145 flags |= SKBEDIT_F_INHERITDSFIELD; 146 } 147 148 parm = nla_data(tb[TCA_SKBEDIT_PARMS]); 149 150 err = tcf_idr_check_alloc(tn, &parm->index, a, bind); 151 if (err < 0) 152 return err; 153 exists = err; 154 if (exists && bind) 155 return 0; 156 157 if (!flags) { 158 if (exists) 159 tcf_idr_release(*a, bind); 160 else 161 tcf_idr_cleanup(tn, parm->index); 162 return -EINVAL; 163 } 164 165 if (!exists) { 166 ret = tcf_idr_create(tn, parm->index, est, a, 167 &act_skbedit_ops, bind, true); 168 if (ret) { 169 tcf_idr_cleanup(tn, parm->index); 170 return ret; 171 } 172 173 d = to_skbedit(*a); 174 ret = ACT_P_CREATED; 175 } else { 176 d = to_skbedit(*a); 177 if (!ovr) { 178 tcf_idr_release(*a, bind); 179 return -EEXIST; 180 } 181 } 182 err = tcf_action_check_ctrlact(parm->action, tp, &goto_ch, extack); 183 if (err < 0) 184 goto release_idr; 185 186 params_new = kzalloc(sizeof(*params_new), GFP_KERNEL); 187 if (unlikely(!params_new)) { 188 err = -ENOMEM; 189 goto put_chain; 190 } 191 192 params_new->flags = flags; 193 if (flags & SKBEDIT_F_PRIORITY) 194 params_new->priority = *priority; 195 if (flags & SKBEDIT_F_QUEUE_MAPPING) 196 params_new->queue_mapping = *queue_mapping; 197 if (flags & SKBEDIT_F_MARK) 198 params_new->mark = *mark; 199 if (flags & SKBEDIT_F_PTYPE) 200 params_new->ptype = *ptype; 201 /* default behaviour is to use all the bits */ 202 params_new->mask = 0xffffffff; 203 if (flags & SKBEDIT_F_MASK) 204 params_new->mask = *mask; 205 206 spin_lock_bh(&d->tcf_lock); 207 goto_ch = tcf_action_set_ctrlact(*a, parm->action, goto_ch); 208 rcu_swap_protected(d->params, params_new, 209 lockdep_is_held(&d->tcf_lock)); 210 spin_unlock_bh(&d->tcf_lock); 211 if (params_new) 212 kfree_rcu(params_new, rcu); 213 if (goto_ch) 214 tcf_chain_put_by_act(goto_ch); 215 216 if (ret == ACT_P_CREATED) 217 tcf_idr_insert(tn, *a); 218 return ret; 219 put_chain: 220 if (goto_ch) 221 tcf_chain_put_by_act(goto_ch); 222 release_idr: 223 tcf_idr_release(*a, bind); 224 return err; 225 } 226 227 static int tcf_skbedit_dump(struct sk_buff *skb, struct tc_action *a, 228 int bind, int ref) 229 { 230 unsigned char *b = skb_tail_pointer(skb); 231 struct tcf_skbedit *d = to_skbedit(a); 232 struct tcf_skbedit_params *params; 233 struct tc_skbedit opt = { 234 .index = d->tcf_index, 235 .refcnt = refcount_read(&d->tcf_refcnt) - ref, 236 .bindcnt = atomic_read(&d->tcf_bindcnt) - bind, 237 }; 238 u64 pure_flags = 0; 239 struct tcf_t t; 240 241 spin_lock_bh(&d->tcf_lock); 242 params = rcu_dereference_protected(d->params, 243 lockdep_is_held(&d->tcf_lock)); 244 opt.action = d->tcf_action; 245 246 if (nla_put(skb, TCA_SKBEDIT_PARMS, sizeof(opt), &opt)) 247 goto nla_put_failure; 248 if ((params->flags & SKBEDIT_F_PRIORITY) && 249 nla_put_u32(skb, TCA_SKBEDIT_PRIORITY, params->priority)) 250 goto nla_put_failure; 251 if ((params->flags & SKBEDIT_F_QUEUE_MAPPING) && 252 nla_put_u16(skb, TCA_SKBEDIT_QUEUE_MAPPING, params->queue_mapping)) 253 goto nla_put_failure; 254 if ((params->flags & SKBEDIT_F_MARK) && 255 nla_put_u32(skb, TCA_SKBEDIT_MARK, params->mark)) 256 goto nla_put_failure; 257 if ((params->flags & SKBEDIT_F_PTYPE) && 258 nla_put_u16(skb, TCA_SKBEDIT_PTYPE, params->ptype)) 259 goto nla_put_failure; 260 if ((params->flags & SKBEDIT_F_MASK) && 261 nla_put_u32(skb, TCA_SKBEDIT_MASK, params->mask)) 262 goto nla_put_failure; 263 if (params->flags & SKBEDIT_F_INHERITDSFIELD) 264 pure_flags |= SKBEDIT_F_INHERITDSFIELD; 265 if (pure_flags != 0 && 266 nla_put(skb, TCA_SKBEDIT_FLAGS, sizeof(pure_flags), &pure_flags)) 267 goto nla_put_failure; 268 269 tcf_tm_dump(&t, &d->tcf_tm); 270 if (nla_put_64bit(skb, TCA_SKBEDIT_TM, sizeof(t), &t, TCA_SKBEDIT_PAD)) 271 goto nla_put_failure; 272 spin_unlock_bh(&d->tcf_lock); 273 274 return skb->len; 275 276 nla_put_failure: 277 spin_unlock_bh(&d->tcf_lock); 278 nlmsg_trim(skb, b); 279 return -1; 280 } 281 282 static void tcf_skbedit_cleanup(struct tc_action *a) 283 { 284 struct tcf_skbedit *d = to_skbedit(a); 285 struct tcf_skbedit_params *params; 286 287 params = rcu_dereference_protected(d->params, 1); 288 if (params) 289 kfree_rcu(params, rcu); 290 } 291 292 static int tcf_skbedit_walker(struct net *net, struct sk_buff *skb, 293 struct netlink_callback *cb, int type, 294 const struct tc_action_ops *ops, 295 struct netlink_ext_ack *extack) 296 { 297 struct tc_action_net *tn = net_generic(net, skbedit_net_id); 298 299 return tcf_generic_walker(tn, skb, cb, type, ops, extack); 300 } 301 302 static int tcf_skbedit_search(struct net *net, struct tc_action **a, u32 index) 303 { 304 struct tc_action_net *tn = net_generic(net, skbedit_net_id); 305 306 return tcf_idr_search(tn, a, index); 307 } 308 309 static struct tc_action_ops act_skbedit_ops = { 310 .kind = "skbedit", 311 .id = TCA_ID_SKBEDIT, 312 .owner = THIS_MODULE, 313 .act = tcf_skbedit_act, 314 .dump = tcf_skbedit_dump, 315 .init = tcf_skbedit_init, 316 .cleanup = tcf_skbedit_cleanup, 317 .walk = tcf_skbedit_walker, 318 .lookup = tcf_skbedit_search, 319 .size = sizeof(struct tcf_skbedit), 320 }; 321 322 static __net_init int skbedit_init_net(struct net *net) 323 { 324 struct tc_action_net *tn = net_generic(net, skbedit_net_id); 325 326 return tc_action_net_init(tn, &act_skbedit_ops); 327 } 328 329 static void __net_exit skbedit_exit_net(struct list_head *net_list) 330 { 331 tc_action_net_exit(net_list, skbedit_net_id); 332 } 333 334 static struct pernet_operations skbedit_net_ops = { 335 .init = skbedit_init_net, 336 .exit_batch = skbedit_exit_net, 337 .id = &skbedit_net_id, 338 .size = sizeof(struct tc_action_net), 339 }; 340 341 MODULE_AUTHOR("Alexander Duyck, <alexander.h.duyck@intel.com>"); 342 MODULE_DESCRIPTION("SKB Editing"); 343 MODULE_LICENSE("GPL"); 344 345 static int __init skbedit_init_module(void) 346 { 347 return tcf_register_action(&act_skbedit_ops, &skbedit_net_ops); 348 } 349 350 static void __exit skbedit_cleanup_module(void) 351 { 352 tcf_unregister_action(&act_skbedit_ops, &skbedit_net_ops); 353 } 354 355 module_init(skbedit_init_module); 356 module_exit(skbedit_cleanup_module); 357