1 /* 2 * net/sched/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 static struct tcf_common *tcf_pedit_ht[PEDIT_TAB_MASK + 1]; 28 static u32 pedit_idx_gen; 29 static DEFINE_RWLOCK(pedit_lock); 30 31 static struct tcf_hashinfo pedit_hash_info = { 32 .htab = tcf_pedit_ht, 33 .hmask = PEDIT_TAB_MASK, 34 .lock = &pedit_lock, 35 }; 36 37 static const struct nla_policy pedit_policy[TCA_PEDIT_MAX + 1] = { 38 [TCA_PEDIT_PARMS] = { .len = sizeof(struct tc_pedit) }, 39 }; 40 41 static int tcf_pedit_init(struct net *net, struct nlattr *nla, 42 struct nlattr *est, struct tc_action *a, 43 int ovr, int bind) 44 { 45 struct nlattr *tb[TCA_PEDIT_MAX + 1]; 46 struct tc_pedit *parm; 47 int ret = 0, err; 48 struct tcf_pedit *p; 49 struct tcf_common *pc; 50 struct tc_pedit_key *keys = NULL; 51 int ksize; 52 53 if (nla == NULL) 54 return -EINVAL; 55 56 err = nla_parse_nested(tb, TCA_PEDIT_MAX, nla, pedit_policy); 57 if (err < 0) 58 return err; 59 60 if (tb[TCA_PEDIT_PARMS] == NULL) 61 return -EINVAL; 62 parm = nla_data(tb[TCA_PEDIT_PARMS]); 63 ksize = parm->nkeys * sizeof(struct tc_pedit_key); 64 if (nla_len(tb[TCA_PEDIT_PARMS]) < sizeof(*parm) + ksize) 65 return -EINVAL; 66 67 pc = tcf_hash_check(parm->index, a, bind, &pedit_hash_info); 68 if (!pc) { 69 if (!parm->nkeys) 70 return -EINVAL; 71 pc = tcf_hash_create(parm->index, est, a, sizeof(*p), bind, 72 &pedit_idx_gen, &pedit_hash_info); 73 if (IS_ERR(pc)) 74 return PTR_ERR(pc); 75 p = to_pedit(pc); 76 keys = kmalloc(ksize, GFP_KERNEL); 77 if (keys == NULL) { 78 if (est) 79 gen_kill_estimator(&pc->tcfc_bstats, 80 &pc->tcfc_rate_est); 81 kfree_rcu(pc, tcfc_rcu); 82 return -ENOMEM; 83 } 84 ret = ACT_P_CREATED; 85 } else { 86 p = to_pedit(pc); 87 tcf_hash_release(pc, bind, &pedit_hash_info); 88 if (bind) 89 return 0; 90 if (!ovr) 91 return -EEXIST; 92 93 if (p->tcfp_nkeys && p->tcfp_nkeys != parm->nkeys) { 94 keys = kmalloc(ksize, GFP_KERNEL); 95 if (keys == NULL) 96 return -ENOMEM; 97 } 98 } 99 100 spin_lock_bh(&p->tcf_lock); 101 p->tcfp_flags = parm->flags; 102 p->tcf_action = parm->action; 103 if (keys) { 104 kfree(p->tcfp_keys); 105 p->tcfp_keys = keys; 106 p->tcfp_nkeys = parm->nkeys; 107 } 108 memcpy(p->tcfp_keys, parm->keys, ksize); 109 spin_unlock_bh(&p->tcf_lock); 110 if (ret == ACT_P_CREATED) 111 tcf_hash_insert(pc, &pedit_hash_info); 112 return ret; 113 } 114 115 static int tcf_pedit_cleanup(struct tc_action *a, int bind) 116 { 117 struct tcf_pedit *p = a->priv; 118 119 if (p) { 120 struct tc_pedit_key *keys = p->tcfp_keys; 121 if (tcf_hash_release(&p->common, bind, &pedit_hash_info)) { 122 kfree(keys); 123 return 1; 124 } 125 } 126 return 0; 127 } 128 129 static int tcf_pedit(struct sk_buff *skb, const struct tc_action *a, 130 struct tcf_result *res) 131 { 132 struct tcf_pedit *p = a->priv; 133 int i, munged = 0; 134 unsigned int off; 135 136 if (skb_unclone(skb, GFP_ATOMIC)) 137 return p->tcf_action; 138 139 off = skb_network_offset(skb); 140 141 spin_lock(&p->tcf_lock); 142 143 p->tcf_tm.lastuse = jiffies; 144 145 if (p->tcfp_nkeys > 0) { 146 struct tc_pedit_key *tkey = p->tcfp_keys; 147 148 for (i = p->tcfp_nkeys; i > 0; i--, tkey++) { 149 u32 *ptr, _data; 150 int offset = tkey->off; 151 152 if (tkey->offmask) { 153 char *d, _d; 154 155 d = skb_header_pointer(skb, off + tkey->at, 1, 156 &_d); 157 if (!d) 158 goto bad; 159 offset += (*d & tkey->offmask) >> tkey->shift; 160 } 161 162 if (offset % 4) { 163 pr_info("tc filter pedit" 164 " offset must be on 32 bit boundaries\n"); 165 goto bad; 166 } 167 if (offset > 0 && offset > skb->len) { 168 pr_info("tc filter pedit" 169 " offset %d can't exceed pkt length %d\n", 170 offset, skb->len); 171 goto bad; 172 } 173 174 ptr = skb_header_pointer(skb, off + offset, 4, &_data); 175 if (!ptr) 176 goto bad; 177 /* just do it, baby */ 178 *ptr = ((*ptr & tkey->mask) ^ tkey->val); 179 if (ptr == &_data) 180 skb_store_bits(skb, off + offset, ptr, 4); 181 munged++; 182 } 183 184 if (munged) 185 skb->tc_verd = SET_TC_MUNGED(skb->tc_verd); 186 goto done; 187 } else 188 WARN(1, "pedit BUG: index %d\n", p->tcf_index); 189 190 bad: 191 p->tcf_qstats.overlimits++; 192 done: 193 bstats_update(&p->tcf_bstats, skb); 194 spin_unlock(&p->tcf_lock); 195 return p->tcf_action; 196 } 197 198 static int tcf_pedit_dump(struct sk_buff *skb, struct tc_action *a, 199 int bind, int ref) 200 { 201 unsigned char *b = skb_tail_pointer(skb); 202 struct tcf_pedit *p = a->priv; 203 struct tc_pedit *opt; 204 struct tcf_t t; 205 int s; 206 207 s = sizeof(*opt) + p->tcfp_nkeys * sizeof(struct tc_pedit_key); 208 209 /* netlink spinlocks held above us - must use ATOMIC */ 210 opt = kzalloc(s, GFP_ATOMIC); 211 if (unlikely(!opt)) 212 return -ENOBUFS; 213 214 memcpy(opt->keys, p->tcfp_keys, 215 p->tcfp_nkeys * sizeof(struct tc_pedit_key)); 216 opt->index = p->tcf_index; 217 opt->nkeys = p->tcfp_nkeys; 218 opt->flags = p->tcfp_flags; 219 opt->action = p->tcf_action; 220 opt->refcnt = p->tcf_refcnt - ref; 221 opt->bindcnt = p->tcf_bindcnt - bind; 222 223 if (nla_put(skb, TCA_PEDIT_PARMS, s, opt)) 224 goto nla_put_failure; 225 t.install = jiffies_to_clock_t(jiffies - p->tcf_tm.install); 226 t.lastuse = jiffies_to_clock_t(jiffies - p->tcf_tm.lastuse); 227 t.expires = jiffies_to_clock_t(p->tcf_tm.expires); 228 if (nla_put(skb, TCA_PEDIT_TM, sizeof(t), &t)) 229 goto nla_put_failure; 230 kfree(opt); 231 return skb->len; 232 233 nla_put_failure: 234 nlmsg_trim(skb, b); 235 kfree(opt); 236 return -1; 237 } 238 239 static struct tc_action_ops act_pedit_ops = { 240 .kind = "pedit", 241 .hinfo = &pedit_hash_info, 242 .type = TCA_ACT_PEDIT, 243 .capab = TCA_CAP_NONE, 244 .owner = THIS_MODULE, 245 .act = tcf_pedit, 246 .dump = tcf_pedit_dump, 247 .cleanup = tcf_pedit_cleanup, 248 .init = tcf_pedit_init, 249 }; 250 251 MODULE_AUTHOR("Jamal Hadi Salim(2002-4)"); 252 MODULE_DESCRIPTION("Generic Packet Editor actions"); 253 MODULE_LICENSE("GPL"); 254 255 static int __init pedit_init_module(void) 256 { 257 return tcf_register_action(&act_pedit_ops); 258 } 259 260 static void __exit pedit_cleanup_module(void) 261 { 262 tcf_unregister_action(&act_pedit_ops); 263 } 264 265 module_init(pedit_init_module); 266 module_exit(pedit_cleanup_module); 267 268