act_mirred.c 6.2 KB

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  1. /*
  2. * net/sched/mirred.c packet mirroring and redirect actions
  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. * TODO: Add ingress support (and socket redirect support)
  12. *
  13. */
  14. #include <asm/uaccess.h>
  15. #include <asm/system.h>
  16. #include <asm/bitops.h>
  17. #include <linux/types.h>
  18. #include <linux/kernel.h>
  19. #include <linux/string.h>
  20. #include <linux/mm.h>
  21. #include <linux/socket.h>
  22. #include <linux/sockios.h>
  23. #include <linux/in.h>
  24. #include <linux/errno.h>
  25. #include <linux/interrupt.h>
  26. #include <linux/netdevice.h>
  27. #include <linux/skbuff.h>
  28. #include <linux/rtnetlink.h>
  29. #include <linux/module.h>
  30. #include <linux/init.h>
  31. #include <linux/proc_fs.h>
  32. #include <net/sock.h>
  33. #include <net/pkt_sched.h>
  34. #include <linux/tc_act/tc_mirred.h>
  35. #include <net/tc_act/tc_mirred.h>
  36. #include <linux/etherdevice.h>
  37. #include <linux/if_arp.h>
  38. #define MIRRED_TAB_MASK 7
  39. static struct tcf_common *tcf_mirred_ht[MIRRED_TAB_MASK + 1];
  40. static u32 mirred_idx_gen;
  41. static DEFINE_RWLOCK(mirred_lock);
  42. static struct tcf_hashinfo mirred_hash_info = {
  43. .htab = tcf_mirred_ht,
  44. .hmask = MIRRED_TAB_MASK,
  45. .lock = &mirred_lock,
  46. };
  47. static inline int tcf_mirred_release(struct tcf_mirred *m, int bind)
  48. {
  49. if (m) {
  50. if (bind)
  51. m->tcf_bindcnt--;
  52. m->tcf_refcnt--;
  53. if(!m->tcf_bindcnt && m->tcf_refcnt <= 0) {
  54. dev_put(m->tcfm_dev);
  55. tcf_hash_destroy(&m->common, &mirred_hash_info);
  56. return 1;
  57. }
  58. }
  59. return 0;
  60. }
  61. static int tcf_mirred_init(struct rtattr *rta, struct rtattr *est,
  62. struct tc_action *a, int ovr, int bind)
  63. {
  64. struct rtattr *tb[TCA_MIRRED_MAX];
  65. struct tc_mirred *parm;
  66. struct tcf_mirred *m;
  67. struct tcf_common *pc;
  68. struct net_device *dev = NULL;
  69. int ret = 0;
  70. int ok_push = 0;
  71. if (rta == NULL || rtattr_parse_nested(tb, TCA_MIRRED_MAX, rta) < 0)
  72. return -EINVAL;
  73. if (tb[TCA_MIRRED_PARMS-1] == NULL ||
  74. RTA_PAYLOAD(tb[TCA_MIRRED_PARMS-1]) < sizeof(*parm))
  75. return -EINVAL;
  76. parm = RTA_DATA(tb[TCA_MIRRED_PARMS-1]);
  77. if (parm->ifindex) {
  78. dev = __dev_get_by_index(parm->ifindex);
  79. if (dev == NULL)
  80. return -ENODEV;
  81. switch (dev->type) {
  82. case ARPHRD_TUNNEL:
  83. case ARPHRD_TUNNEL6:
  84. case ARPHRD_SIT:
  85. case ARPHRD_IPGRE:
  86. case ARPHRD_VOID:
  87. case ARPHRD_NONE:
  88. ok_push = 0;
  89. break;
  90. default:
  91. ok_push = 1;
  92. break;
  93. }
  94. }
  95. pc = tcf_hash_check(parm->index, a, bind, &mirred_hash_info);
  96. if (!pc) {
  97. if (!parm->ifindex)
  98. return -EINVAL;
  99. pc = tcf_hash_create(parm->index, est, a, sizeof(*m), bind,
  100. &mirred_idx_gen, &mirred_hash_info);
  101. if (unlikely(!pc))
  102. return -ENOMEM;
  103. ret = ACT_P_CREATED;
  104. } else {
  105. if (!ovr) {
  106. tcf_mirred_release(to_mirred(pc), bind);
  107. return -EEXIST;
  108. }
  109. }
  110. m = to_mirred(pc);
  111. spin_lock_bh(&m->tcf_lock);
  112. m->tcf_action = parm->action;
  113. m->tcfm_eaction = parm->eaction;
  114. if (parm->ifindex) {
  115. m->tcfm_ifindex = parm->ifindex;
  116. if (ret != ACT_P_CREATED)
  117. dev_put(m->tcfm_dev);
  118. m->tcfm_dev = dev;
  119. dev_hold(dev);
  120. m->tcfm_ok_push = ok_push;
  121. }
  122. spin_unlock_bh(&m->tcf_lock);
  123. if (ret == ACT_P_CREATED)
  124. tcf_hash_insert(pc, &mirred_hash_info);
  125. return ret;
  126. }
  127. static int tcf_mirred_cleanup(struct tc_action *a, int bind)
  128. {
  129. struct tcf_mirred *m = a->priv;
  130. if (m)
  131. return tcf_mirred_release(m, bind);
  132. return 0;
  133. }
  134. static int tcf_mirred(struct sk_buff *skb, struct tc_action *a,
  135. struct tcf_result *res)
  136. {
  137. struct tcf_mirred *m = a->priv;
  138. struct net_device *dev;
  139. struct sk_buff *skb2 = NULL;
  140. u32 at = G_TC_AT(skb->tc_verd);
  141. spin_lock(&m->tcf_lock);
  142. dev = m->tcfm_dev;
  143. m->tcf_tm.lastuse = jiffies;
  144. if (!(dev->flags&IFF_UP) ) {
  145. if (net_ratelimit())
  146. printk("mirred to Houston: device %s is gone!\n",
  147. dev->name);
  148. bad_mirred:
  149. if (skb2 != NULL)
  150. kfree_skb(skb2);
  151. m->tcf_qstats.overlimits++;
  152. m->tcf_bstats.bytes += skb->len;
  153. m->tcf_bstats.packets++;
  154. spin_unlock(&m->tcf_lock);
  155. /* should we be asking for packet to be dropped?
  156. * may make sense for redirect case only
  157. */
  158. return TC_ACT_SHOT;
  159. }
  160. skb2 = skb_clone(skb, GFP_ATOMIC);
  161. if (skb2 == NULL)
  162. goto bad_mirred;
  163. if (m->tcfm_eaction != TCA_EGRESS_MIRROR &&
  164. m->tcfm_eaction != TCA_EGRESS_REDIR) {
  165. if (net_ratelimit())
  166. printk("tcf_mirred unknown action %d\n",
  167. m->tcfm_eaction);
  168. goto bad_mirred;
  169. }
  170. m->tcf_bstats.bytes += skb2->len;
  171. m->tcf_bstats.packets++;
  172. if (!(at & AT_EGRESS))
  173. if (m->tcfm_ok_push)
  174. skb_push(skb2, skb2->dev->hard_header_len);
  175. /* mirror is always swallowed */
  176. if (m->tcfm_eaction != TCA_EGRESS_MIRROR)
  177. skb2->tc_verd = SET_TC_FROM(skb2->tc_verd, at);
  178. skb2->dev = dev;
  179. skb2->iif = skb->dev->ifindex;
  180. dev_queue_xmit(skb2);
  181. spin_unlock(&m->tcf_lock);
  182. return m->tcf_action;
  183. }
  184. static int tcf_mirred_dump(struct sk_buff *skb, struct tc_action *a, int bind, int ref)
  185. {
  186. unsigned char *b = skb->tail;
  187. struct tcf_mirred *m = a->priv;
  188. struct tc_mirred opt;
  189. struct tcf_t t;
  190. opt.index = m->tcf_index;
  191. opt.action = m->tcf_action;
  192. opt.refcnt = m->tcf_refcnt - ref;
  193. opt.bindcnt = m->tcf_bindcnt - bind;
  194. opt.eaction = m->tcfm_eaction;
  195. opt.ifindex = m->tcfm_ifindex;
  196. RTA_PUT(skb, TCA_MIRRED_PARMS, sizeof(opt), &opt);
  197. t.install = jiffies_to_clock_t(jiffies - m->tcf_tm.install);
  198. t.lastuse = jiffies_to_clock_t(jiffies - m->tcf_tm.lastuse);
  199. t.expires = jiffies_to_clock_t(m->tcf_tm.expires);
  200. RTA_PUT(skb, TCA_MIRRED_TM, sizeof(t), &t);
  201. return skb->len;
  202. rtattr_failure:
  203. skb_trim(skb, b - skb->data);
  204. return -1;
  205. }
  206. static struct tc_action_ops act_mirred_ops = {
  207. .kind = "mirred",
  208. .hinfo = &mirred_hash_info,
  209. .type = TCA_ACT_MIRRED,
  210. .capab = TCA_CAP_NONE,
  211. .owner = THIS_MODULE,
  212. .act = tcf_mirred,
  213. .dump = tcf_mirred_dump,
  214. .cleanup = tcf_mirred_cleanup,
  215. .lookup = tcf_hash_search,
  216. .init = tcf_mirred_init,
  217. .walk = tcf_generic_walker
  218. };
  219. MODULE_AUTHOR("Jamal Hadi Salim(2002)");
  220. MODULE_DESCRIPTION("Device Mirror/redirect actions");
  221. MODULE_LICENSE("GPL");
  222. static int __init mirred_init_module(void)
  223. {
  224. printk("Mirror/redirect action on\n");
  225. return tcf_register_action(&act_mirred_ops);
  226. }
  227. static void __exit mirred_cleanup_module(void)
  228. {
  229. tcf_unregister_action(&act_mirred_ops);
  230. }
  231. module_init(mirred_init_module);
  232. module_exit(mirred_cleanup_module);