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