Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 1 | /* |
| 2 | * net/sched/ipt.c iptables target interface |
| 3 | * |
| 4 | *TODO: Add other tables. For now we only support the ipv4 table targets |
| 5 | * |
| 6 | * This program is free software; you can redistribute it and/or |
| 7 | * modify it under the terms of the GNU General Public License |
| 8 | * as published by the Free Software Foundation; either version |
| 9 | * 2 of the License, or (at your option) any later version. |
| 10 | * |
| 11 | * Copyright: Jamal Hadi Salim (2002-4) |
| 12 | */ |
| 13 | |
| 14 | #include <asm/uaccess.h> |
| 15 | #include <asm/system.h> |
| 16 | #include <asm/bitops.h> |
| 17 | #include <linux/config.h> |
| 18 | #include <linux/types.h> |
| 19 | #include <linux/kernel.h> |
| 20 | #include <linux/sched.h> |
| 21 | #include <linux/string.h> |
| 22 | #include <linux/mm.h> |
| 23 | #include <linux/socket.h> |
| 24 | #include <linux/sockios.h> |
| 25 | #include <linux/in.h> |
| 26 | #include <linux/errno.h> |
| 27 | #include <linux/interrupt.h> |
| 28 | #include <linux/netdevice.h> |
| 29 | #include <linux/skbuff.h> |
| 30 | #include <linux/rtnetlink.h> |
| 31 | #include <linux/module.h> |
| 32 | #include <linux/init.h> |
| 33 | #include <linux/proc_fs.h> |
| 34 | #include <linux/kmod.h> |
| 35 | #include <net/sock.h> |
| 36 | #include <net/pkt_sched.h> |
| 37 | #include <linux/tc_act/tc_ipt.h> |
| 38 | #include <net/tc_act/tc_ipt.h> |
| 39 | |
| 40 | #include <linux/netfilter_ipv4/ip_tables.h> |
| 41 | |
| 42 | /* use generic hash table */ |
| 43 | #define MY_TAB_SIZE 16 |
| 44 | #define MY_TAB_MASK 15 |
| 45 | |
| 46 | static u32 idx_gen; |
| 47 | static struct tcf_ipt *tcf_ipt_ht[MY_TAB_SIZE]; |
| 48 | /* ipt hash table lock */ |
| 49 | static DEFINE_RWLOCK(ipt_lock); |
| 50 | |
| 51 | /* ovewrride the defaults */ |
| 52 | #define tcf_st tcf_ipt |
| 53 | #define tcf_t_lock ipt_lock |
| 54 | #define tcf_ht tcf_ipt_ht |
| 55 | |
| 56 | #define CONFIG_NET_ACT_INIT |
| 57 | #include <net/pkt_act.h> |
| 58 | |
| 59 | static int |
| 60 | ipt_init_target(struct ipt_entry_target *t, char *table, unsigned int hook) |
| 61 | { |
| 62 | struct ipt_target *target; |
| 63 | int ret = 0; |
| 64 | |
Harald Welte | 2e4e6a1 | 2006-01-12 13:30:04 -0800 | [diff] [blame^] | 65 | target = xt_find_target(AF_INET, t->u.user.name, t->u.user.revision); |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 66 | if (!target) |
| 67 | return -ENOENT; |
| 68 | |
| 69 | DPRINTK("ipt_init_target: found %s\n", target->name); |
| 70 | t->u.kernel.target = target; |
| 71 | |
| 72 | if (t->u.kernel.target->checkentry |
| 73 | && !t->u.kernel.target->checkentry(table, NULL, t->data, |
| 74 | t->u.target_size - sizeof(*t), |
| 75 | hook)) { |
| 76 | DPRINTK("ipt_init_target: check failed for `%s'.\n", |
| 77 | t->u.kernel.target->name); |
| 78 | module_put(t->u.kernel.target->me); |
| 79 | ret = -EINVAL; |
| 80 | } |
| 81 | |
| 82 | return ret; |
| 83 | } |
| 84 | |
| 85 | static void |
| 86 | ipt_destroy_target(struct ipt_entry_target *t) |
| 87 | { |
| 88 | if (t->u.kernel.target->destroy) |
| 89 | t->u.kernel.target->destroy(t->data, |
| 90 | t->u.target_size - sizeof(*t)); |
| 91 | module_put(t->u.kernel.target->me); |
| 92 | } |
| 93 | |
| 94 | static int |
| 95 | tcf_ipt_release(struct tcf_ipt *p, int bind) |
| 96 | { |
| 97 | int ret = 0; |
| 98 | if (p) { |
| 99 | if (bind) |
| 100 | p->bindcnt--; |
| 101 | p->refcnt--; |
| 102 | if (p->bindcnt <= 0 && p->refcnt <= 0) { |
| 103 | ipt_destroy_target(p->t); |
| 104 | kfree(p->tname); |
| 105 | kfree(p->t); |
| 106 | tcf_hash_destroy(p); |
| 107 | ret = ACT_P_DELETED; |
| 108 | } |
| 109 | } |
| 110 | return ret; |
| 111 | } |
| 112 | |
| 113 | static int |
| 114 | tcf_ipt_init(struct rtattr *rta, struct rtattr *est, struct tc_action *a, |
| 115 | int ovr, int bind) |
| 116 | { |
| 117 | struct rtattr *tb[TCA_IPT_MAX]; |
| 118 | struct tcf_ipt *p; |
| 119 | struct ipt_entry_target *td, *t; |
| 120 | char *tname; |
| 121 | int ret = 0, err; |
| 122 | u32 hook = 0; |
| 123 | u32 index = 0; |
| 124 | |
| 125 | if (rta == NULL || rtattr_parse_nested(tb, TCA_IPT_MAX, rta) < 0) |
| 126 | return -EINVAL; |
| 127 | |
| 128 | if (tb[TCA_IPT_HOOK-1] == NULL || |
| 129 | RTA_PAYLOAD(tb[TCA_IPT_HOOK-1]) < sizeof(u32)) |
| 130 | return -EINVAL; |
| 131 | if (tb[TCA_IPT_TARG-1] == NULL || |
| 132 | RTA_PAYLOAD(tb[TCA_IPT_TARG-1]) < sizeof(*t)) |
| 133 | return -EINVAL; |
| 134 | td = (struct ipt_entry_target *)RTA_DATA(tb[TCA_IPT_TARG-1]); |
| 135 | if (RTA_PAYLOAD(tb[TCA_IPT_TARG-1]) < td->u.target_size) |
| 136 | return -EINVAL; |
| 137 | |
| 138 | if (tb[TCA_IPT_INDEX-1] != NULL && |
| 139 | RTA_PAYLOAD(tb[TCA_IPT_INDEX-1]) >= sizeof(u32)) |
| 140 | index = *(u32 *)RTA_DATA(tb[TCA_IPT_INDEX-1]); |
| 141 | |
| 142 | p = tcf_hash_check(index, a, ovr, bind); |
| 143 | if (p == NULL) { |
| 144 | p = tcf_hash_create(index, est, a, sizeof(*p), ovr, bind); |
| 145 | if (p == NULL) |
| 146 | return -ENOMEM; |
| 147 | ret = ACT_P_CREATED; |
| 148 | } else { |
| 149 | if (!ovr) { |
| 150 | tcf_ipt_release(p, bind); |
| 151 | return -EEXIST; |
| 152 | } |
| 153 | } |
| 154 | |
| 155 | hook = *(u32 *)RTA_DATA(tb[TCA_IPT_HOOK-1]); |
| 156 | |
| 157 | err = -ENOMEM; |
| 158 | tname = kmalloc(IFNAMSIZ, GFP_KERNEL); |
| 159 | if (tname == NULL) |
| 160 | goto err1; |
| 161 | if (tb[TCA_IPT_TABLE - 1] == NULL || |
| 162 | rtattr_strlcpy(tname, tb[TCA_IPT_TABLE-1], IFNAMSIZ) >= IFNAMSIZ) |
| 163 | strcpy(tname, "mangle"); |
| 164 | |
| 165 | t = kmalloc(td->u.target_size, GFP_KERNEL); |
| 166 | if (t == NULL) |
| 167 | goto err2; |
| 168 | memcpy(t, td, td->u.target_size); |
| 169 | |
| 170 | if ((err = ipt_init_target(t, tname, hook)) < 0) |
| 171 | goto err3; |
| 172 | |
| 173 | spin_lock_bh(&p->lock); |
| 174 | if (ret != ACT_P_CREATED) { |
| 175 | ipt_destroy_target(p->t); |
| 176 | kfree(p->tname); |
| 177 | kfree(p->t); |
| 178 | } |
| 179 | p->tname = tname; |
| 180 | p->t = t; |
| 181 | p->hook = hook; |
| 182 | spin_unlock_bh(&p->lock); |
| 183 | if (ret == ACT_P_CREATED) |
| 184 | tcf_hash_insert(p); |
| 185 | return ret; |
| 186 | |
| 187 | err3: |
| 188 | kfree(t); |
| 189 | err2: |
| 190 | kfree(tname); |
| 191 | err1: |
| 192 | kfree(p); |
| 193 | return err; |
| 194 | } |
| 195 | |
| 196 | static int |
| 197 | tcf_ipt_cleanup(struct tc_action *a, int bind) |
| 198 | { |
| 199 | struct tcf_ipt *p = PRIV(a, ipt); |
| 200 | return tcf_ipt_release(p, bind); |
| 201 | } |
| 202 | |
| 203 | static int |
Patrick McHardy | f43c5a0 | 2006-01-08 22:15:34 -0800 | [diff] [blame] | 204 | tcf_ipt(struct sk_buff *skb, struct tc_action *a, struct tcf_result *res) |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 205 | { |
| 206 | int ret = 0, result = 0; |
| 207 | struct tcf_ipt *p = PRIV(a, ipt); |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 208 | |
| 209 | if (skb_cloned(skb)) { |
| 210 | if (pskb_expand_head(skb, 0, 0, GFP_ATOMIC)) |
| 211 | return TC_ACT_UNSPEC; |
| 212 | } |
| 213 | |
| 214 | spin_lock(&p->lock); |
| 215 | |
| 216 | p->tm.lastuse = jiffies; |
| 217 | p->bstats.bytes += skb->len; |
| 218 | p->bstats.packets++; |
| 219 | |
| 220 | /* yes, we have to worry about both in and out dev |
| 221 | worry later - danger - this API seems to have changed |
| 222 | from earlier kernels */ |
| 223 | |
Patrick McHardy | f43c5a0 | 2006-01-08 22:15:34 -0800 | [diff] [blame] | 224 | /* iptables targets take a double skb pointer in case the skb |
| 225 | * needs to be replaced. We don't own the skb, so this must not |
| 226 | * happen. The pskb_expand_head above should make sure of this */ |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 227 | ret = p->t->u.kernel.target->target(&skb, skb->dev, NULL, |
| 228 | p->hook, p->t->data, NULL); |
| 229 | switch (ret) { |
| 230 | case NF_ACCEPT: |
| 231 | result = TC_ACT_OK; |
| 232 | break; |
| 233 | case NF_DROP: |
| 234 | result = TC_ACT_SHOT; |
| 235 | p->qstats.drops++; |
| 236 | break; |
| 237 | case IPT_CONTINUE: |
| 238 | result = TC_ACT_PIPE; |
| 239 | break; |
| 240 | default: |
| 241 | if (net_ratelimit()) |
| 242 | printk("Bogus netfilter code %d assume ACCEPT\n", ret); |
| 243 | result = TC_POLICE_OK; |
| 244 | break; |
| 245 | } |
| 246 | spin_unlock(&p->lock); |
| 247 | return result; |
| 248 | |
| 249 | } |
| 250 | |
| 251 | static int |
| 252 | tcf_ipt_dump(struct sk_buff *skb, struct tc_action *a, int bind, int ref) |
| 253 | { |
| 254 | struct ipt_entry_target *t; |
| 255 | struct tcf_t tm; |
| 256 | struct tc_cnt c; |
| 257 | unsigned char *b = skb->tail; |
| 258 | struct tcf_ipt *p = PRIV(a, ipt); |
| 259 | |
| 260 | /* for simple targets kernel size == user size |
| 261 | ** user name = target name |
| 262 | ** for foolproof you need to not assume this |
| 263 | */ |
| 264 | |
| 265 | t = kmalloc(p->t->u.user.target_size, GFP_ATOMIC); |
| 266 | if (t == NULL) |
| 267 | goto rtattr_failure; |
| 268 | |
| 269 | c.bindcnt = p->bindcnt - bind; |
| 270 | c.refcnt = p->refcnt - ref; |
| 271 | memcpy(t, p->t, p->t->u.user.target_size); |
| 272 | strcpy(t->u.user.name, p->t->u.kernel.target->name); |
| 273 | |
| 274 | DPRINTK("\ttcf_ipt_dump tablename %s length %d\n", p->tname, |
| 275 | strlen(p->tname)); |
| 276 | DPRINTK("\tdump target name %s size %d size user %d " |
| 277 | "data[0] %x data[1] %x\n", p->t->u.kernel.target->name, |
| 278 | p->t->u.target_size, p->t->u.user.target_size, |
| 279 | p->t->data[0], p->t->data[1]); |
| 280 | RTA_PUT(skb, TCA_IPT_TARG, p->t->u.user.target_size, t); |
| 281 | RTA_PUT(skb, TCA_IPT_INDEX, 4, &p->index); |
| 282 | RTA_PUT(skb, TCA_IPT_HOOK, 4, &p->hook); |
| 283 | RTA_PUT(skb, TCA_IPT_CNT, sizeof(struct tc_cnt), &c); |
| 284 | RTA_PUT(skb, TCA_IPT_TABLE, IFNAMSIZ, p->tname); |
| 285 | tm.install = jiffies_to_clock_t(jiffies - p->tm.install); |
| 286 | tm.lastuse = jiffies_to_clock_t(jiffies - p->tm.lastuse); |
| 287 | tm.expires = jiffies_to_clock_t(p->tm.expires); |
| 288 | RTA_PUT(skb, TCA_IPT_TM, sizeof (tm), &tm); |
| 289 | kfree(t); |
| 290 | return skb->len; |
| 291 | |
| 292 | rtattr_failure: |
| 293 | skb_trim(skb, b - skb->data); |
| 294 | kfree(t); |
| 295 | return -1; |
| 296 | } |
| 297 | |
| 298 | static struct tc_action_ops act_ipt_ops = { |
| 299 | .kind = "ipt", |
| 300 | .type = TCA_ACT_IPT, |
| 301 | .capab = TCA_CAP_NONE, |
| 302 | .owner = THIS_MODULE, |
| 303 | .act = tcf_ipt, |
| 304 | .dump = tcf_ipt_dump, |
| 305 | .cleanup = tcf_ipt_cleanup, |
| 306 | .lookup = tcf_hash_search, |
| 307 | .init = tcf_ipt_init, |
| 308 | .walk = tcf_generic_walker |
| 309 | }; |
| 310 | |
| 311 | MODULE_AUTHOR("Jamal Hadi Salim(2002-4)"); |
| 312 | MODULE_DESCRIPTION("Iptables target actions"); |
| 313 | MODULE_LICENSE("GPL"); |
| 314 | |
| 315 | static int __init |
| 316 | ipt_init_module(void) |
| 317 | { |
| 318 | return tcf_register_action(&act_ipt_ops); |
| 319 | } |
| 320 | |
| 321 | static void __exit |
| 322 | ipt_cleanup_module(void) |
| 323 | { |
| 324 | tcf_unregister_action(&act_ipt_ops); |
| 325 | } |
| 326 | |
| 327 | module_init(ipt_init_module); |
| 328 | module_exit(ipt_cleanup_module); |