1 /* 2 * net/sched/act_pedit.c Generic packet editor 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: Jamal Hadi Salim (2002-4) 10 */ 11 12 #include <linux/types.h> 13 #include <linux/kernel.h> 14 #include <linux/string.h> 15 #include <linux/errno.h> 16 #include <linux/skbuff.h> 17 #include <linux/rtnetlink.h> 18 #include <linux/module.h> 19 #include <linux/init.h> 20 #include <linux/slab.h> 21 #include <net/netlink.h> 22 #include <net/pkt_sched.h> 23 #include <linux/tc_act/tc_pedit.h> 24 #include <net/tc_act/tc_pedit.h> 25 26 #define PEDIT_TAB_MASK 15 27 28 static int pedit_net_id; 29 static struct tc_action_ops act_pedit_ops; 30 31 static const struct nla_policy pedit_policy[TCA_PEDIT_MAX + 1] = { 32 [TCA_PEDIT_PARMS] = { .len = sizeof(struct tc_pedit) }, 33 }; 34 35 static int tcf_pedit_init(struct net *net, struct nlattr *nla, 36 struct nlattr *est, struct tc_action **a, 37 int ovr, int bind) 38 { 39 struct tc_action_net *tn = net_generic(net, pedit_net_id); 40 struct nlattr *tb[TCA_PEDIT_MAX + 1]; 41 struct tc_pedit *parm; 42 int ret = 0, err; 43 struct tcf_pedit *p; 44 struct tc_pedit_key *keys = NULL; 45 int ksize; 46 47 if (nla == NULL) 48 return -EINVAL; 49 50 err = nla_parse_nested(tb, TCA_PEDIT_MAX, nla, pedit_policy); 51 if (err < 0) 52 return err; 53 54 if (tb[TCA_PEDIT_PARMS] == NULL) 55 return -EINVAL; 56 parm = nla_data(tb[TCA_PEDIT_PARMS]); 57 ksize = parm->nkeys * sizeof(struct tc_pedit_key); 58 if (nla_len(tb[TCA_PEDIT_PARMS]) < sizeof(*parm) + ksize) 59 return -EINVAL; 60 61 if (!tcf_hash_check(tn, parm->index, a, bind)) { 62 if (!parm->nkeys) 63 return -EINVAL; 64 ret = tcf_hash_create(tn, parm->index, est, a, 65 &act_pedit_ops, bind, false); 66 if (ret) 67 return ret; 68 p = to_pedit(*a); 69 keys = kmalloc(ksize, GFP_KERNEL); 70 if (keys == NULL) { 71 tcf_hash_cleanup(*a, est); 72 return -ENOMEM; 73 } 74 ret = ACT_P_CREATED; 75 } else { 76 if (bind) 77 return 0; 78 tcf_hash_release(*a, bind); 79 if (!ovr) 80 return -EEXIST; 81 p = to_pedit(*a); 82 if (p->tcfp_nkeys && p->tcfp_nkeys != parm->nkeys) { 83 keys = kmalloc(ksize, GFP_KERNEL); 84 if (keys == NULL) 85 return -ENOMEM; 86 } 87 } 88 89 spin_lock_bh(&p->tcf_lock); 90 p->tcfp_flags = parm->flags; 91 p->tcf_action = parm->action; 92 if (keys) { 93 kfree(p->tcfp_keys); 94 p->tcfp_keys = keys; 95 p->tcfp_nkeys = parm->nkeys; 96 } 97 memcpy(p->tcfp_keys, parm->keys, ksize); 98 spin_unlock_bh(&p->tcf_lock); 99 if (ret == ACT_P_CREATED) 100 tcf_hash_insert(tn, *a); 101 return ret; 102 } 103 104 static void tcf_pedit_cleanup(struct tc_action *a, int bind) 105 { 106 struct tcf_pedit *p = to_pedit(a); 107 struct tc_pedit_key *keys = p->tcfp_keys; 108 kfree(keys); 109 } 110 111 static int tcf_pedit(struct sk_buff *skb, const struct tc_action *a, 112 struct tcf_result *res) 113 { 114 struct tcf_pedit *p = to_pedit(a); 115 int i; 116 unsigned int off; 117 118 if (skb_unclone(skb, GFP_ATOMIC)) 119 return p->tcf_action; 120 121 off = skb_network_offset(skb); 122 123 spin_lock(&p->tcf_lock); 124 125 tcf_lastuse_update(&p->tcf_tm); 126 127 if (p->tcfp_nkeys > 0) { 128 struct tc_pedit_key *tkey = p->tcfp_keys; 129 130 for (i = p->tcfp_nkeys; i > 0; i--, tkey++) { 131 u32 *ptr, _data; 132 int offset = tkey->off; 133 134 if (tkey->offmask) { 135 char *d, _d; 136 137 d = skb_header_pointer(skb, off + tkey->at, 1, 138 &_d); 139 if (!d) 140 goto bad; 141 offset += (*d & tkey->offmask) >> tkey->shift; 142 } 143 144 if (offset % 4) { 145 pr_info("tc filter pedit" 146 " offset must be on 32 bit boundaries\n"); 147 goto bad; 148 } 149 if (offset > 0 && offset > skb->len) { 150 pr_info("tc filter pedit" 151 " offset %d can't exceed pkt length %d\n", 152 offset, skb->len); 153 goto bad; 154 } 155 156 ptr = skb_header_pointer(skb, off + offset, 4, &_data); 157 if (!ptr) 158 goto bad; 159 /* just do it, baby */ 160 *ptr = ((*ptr & tkey->mask) ^ tkey->val); 161 if (ptr == &_data) 162 skb_store_bits(skb, off + offset, ptr, 4); 163 } 164 165 goto done; 166 } else 167 WARN(1, "pedit BUG: index %d\n", p->tcf_index); 168 169 bad: 170 p->tcf_qstats.overlimits++; 171 done: 172 bstats_update(&p->tcf_bstats, skb); 173 spin_unlock(&p->tcf_lock); 174 return p->tcf_action; 175 } 176 177 static int tcf_pedit_dump(struct sk_buff *skb, struct tc_action *a, 178 int bind, int ref) 179 { 180 unsigned char *b = skb_tail_pointer(skb); 181 struct tcf_pedit *p = to_pedit(a); 182 struct tc_pedit *opt; 183 struct tcf_t t; 184 int s; 185 186 s = sizeof(*opt) + p->tcfp_nkeys * sizeof(struct tc_pedit_key); 187 188 /* netlink spinlocks held above us - must use ATOMIC */ 189 opt = kzalloc(s, GFP_ATOMIC); 190 if (unlikely(!opt)) 191 return -ENOBUFS; 192 193 memcpy(opt->keys, p->tcfp_keys, 194 p->tcfp_nkeys * sizeof(struct tc_pedit_key)); 195 opt->index = p->tcf_index; 196 opt->nkeys = p->tcfp_nkeys; 197 opt->flags = p->tcfp_flags; 198 opt->action = p->tcf_action; 199 opt->refcnt = p->tcf_refcnt - ref; 200 opt->bindcnt = p->tcf_bindcnt - bind; 201 202 if (nla_put(skb, TCA_PEDIT_PARMS, s, opt)) 203 goto nla_put_failure; 204 205 tcf_tm_dump(&t, &p->tcf_tm); 206 if (nla_put_64bit(skb, TCA_PEDIT_TM, sizeof(t), &t, TCA_PEDIT_PAD)) 207 goto nla_put_failure; 208 209 kfree(opt); 210 return skb->len; 211 212 nla_put_failure: 213 nlmsg_trim(skb, b); 214 kfree(opt); 215 return -1; 216 } 217 218 static int tcf_pedit_walker(struct net *net, struct sk_buff *skb, 219 struct netlink_callback *cb, int type, 220 const struct tc_action_ops *ops) 221 { 222 struct tc_action_net *tn = net_generic(net, pedit_net_id); 223 224 return tcf_generic_walker(tn, skb, cb, type, ops); 225 } 226 227 static int tcf_pedit_search(struct net *net, struct tc_action **a, u32 index) 228 { 229 struct tc_action_net *tn = net_generic(net, pedit_net_id); 230 231 return tcf_hash_search(tn, a, index); 232 } 233 234 static struct tc_action_ops act_pedit_ops = { 235 .kind = "pedit", 236 .type = TCA_ACT_PEDIT, 237 .owner = THIS_MODULE, 238 .act = tcf_pedit, 239 .dump = tcf_pedit_dump, 240 .cleanup = tcf_pedit_cleanup, 241 .init = tcf_pedit_init, 242 .walk = tcf_pedit_walker, 243 .lookup = tcf_pedit_search, 244 .size = sizeof(struct tcf_pedit), 245 }; 246 247 static __net_init int pedit_init_net(struct net *net) 248 { 249 struct tc_action_net *tn = net_generic(net, pedit_net_id); 250 251 return tc_action_net_init(tn, &act_pedit_ops, PEDIT_TAB_MASK); 252 } 253 254 static void __net_exit pedit_exit_net(struct net *net) 255 { 256 struct tc_action_net *tn = net_generic(net, pedit_net_id); 257 258 tc_action_net_exit(tn); 259 } 260 261 static struct pernet_operations pedit_net_ops = { 262 .init = pedit_init_net, 263 .exit = pedit_exit_net, 264 .id = &pedit_net_id, 265 .size = sizeof(struct tc_action_net), 266 }; 267 268 MODULE_AUTHOR("Jamal Hadi Salim(2002-4)"); 269 MODULE_DESCRIPTION("Generic Packet Editor actions"); 270 MODULE_LICENSE("GPL"); 271 272 static int __init pedit_init_module(void) 273 { 274 return tcf_register_action(&act_pedit_ops, &pedit_net_ops); 275 } 276 277 static void __exit pedit_cleanup_module(void) 278 { 279 tcf_unregister_action(&act_pedit_ops, &pedit_net_ops); 280 } 281 282 module_init(pedit_init_module); 283 module_exit(pedit_cleanup_module); 284 285