atmtcp.c 11 KB

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  1. // SPDX-License-Identifier: GPL-2.0-only
  2. /* drivers/atm/atmtcp.c - ATM over TCP "device" driver */
  3. /* Written 1997-2000 by Werner Almesberger, EPFL LRC/ICA */
  4. #include <linux/module.h>
  5. #include <linux/wait.h>
  6. #include <linux/atmdev.h>
  7. #include <linux/atm_tcp.h>
  8. #include <linux/bitops.h>
  9. #include <linux/init.h>
  10. #include <linux/slab.h>
  11. #include <linux/uaccess.h>
  12. #include <linux/atomic.h>
  13. extern int atm_init_aal5(struct atm_vcc *vcc); /* "raw" AAL5 transport */
  14. #define PRIV(dev) ((struct atmtcp_dev_data *) ((dev)->dev_data))
  15. struct atmtcp_dev_data {
  16. struct atm_vcc *vcc; /* control VCC; NULL if detached */
  17. int persist; /* non-zero if persistent */
  18. };
  19. #define DEV_LABEL "atmtcp"
  20. #define MAX_VPI_BITS 8 /* simplifies life */
  21. #define MAX_VCI_BITS 16
  22. /*
  23. * Hairy code ahead: the control VCC may be closed while we're still
  24. * waiting for an answer, so we need to re-validate out_vcc every once
  25. * in a while.
  26. */
  27. static int atmtcp_send_control(struct atm_vcc *vcc,int type,
  28. const struct atmtcp_control *msg,int flag)
  29. {
  30. DECLARE_WAITQUEUE(wait,current);
  31. struct atm_vcc *out_vcc;
  32. struct sk_buff *skb;
  33. struct atmtcp_control *new_msg;
  34. int old_test;
  35. int error = 0;
  36. out_vcc = PRIV(vcc->dev) ? PRIV(vcc->dev)->vcc : NULL;
  37. if (!out_vcc) return -EUNATCH;
  38. skb = alloc_skb(sizeof(*msg),GFP_KERNEL);
  39. if (!skb) return -ENOMEM;
  40. mb();
  41. out_vcc = PRIV(vcc->dev) ? PRIV(vcc->dev)->vcc : NULL;
  42. if (!out_vcc) {
  43. dev_kfree_skb(skb);
  44. return -EUNATCH;
  45. }
  46. atm_force_charge(out_vcc,skb->truesize);
  47. new_msg = skb_put(skb, sizeof(*new_msg));
  48. *new_msg = *msg;
  49. new_msg->hdr.length = ATMTCP_HDR_MAGIC;
  50. new_msg->type = type;
  51. memset(&new_msg->vcc,0,sizeof(atm_kptr_t));
  52. *(struct atm_vcc **) &new_msg->vcc = vcc;
  53. old_test = test_bit(flag,&vcc->flags);
  54. out_vcc->push(out_vcc,skb);
  55. add_wait_queue(sk_sleep(sk_atm(vcc)), &wait);
  56. while (test_bit(flag,&vcc->flags) == old_test) {
  57. mb();
  58. out_vcc = PRIV(vcc->dev) ? PRIV(vcc->dev)->vcc : NULL;
  59. if (!out_vcc) {
  60. error = -EUNATCH;
  61. break;
  62. }
  63. set_current_state(TASK_UNINTERRUPTIBLE);
  64. schedule();
  65. }
  66. set_current_state(TASK_RUNNING);
  67. remove_wait_queue(sk_sleep(sk_atm(vcc)), &wait);
  68. return error;
  69. }
  70. static int atmtcp_recv_control(const struct atmtcp_control *msg)
  71. {
  72. struct atm_vcc *vcc = *(struct atm_vcc **) &msg->vcc;
  73. vcc->vpi = msg->addr.sap_addr.vpi;
  74. vcc->vci = msg->addr.sap_addr.vci;
  75. vcc->qos = msg->qos;
  76. sk_atm(vcc)->sk_err = -msg->result;
  77. switch (msg->type) {
  78. case ATMTCP_CTRL_OPEN:
  79. change_bit(ATM_VF_READY,&vcc->flags);
  80. break;
  81. case ATMTCP_CTRL_CLOSE:
  82. change_bit(ATM_VF_ADDR,&vcc->flags);
  83. break;
  84. default:
  85. printk(KERN_ERR "atmtcp_recv_control: unknown type %d\n",
  86. msg->type);
  87. return -EINVAL;
  88. }
  89. wake_up(sk_sleep(sk_atm(vcc)));
  90. return 0;
  91. }
  92. static void atmtcp_v_dev_close(struct atm_dev *dev)
  93. {
  94. /* Nothing.... Isn't this simple :-) -- REW */
  95. }
  96. static int atmtcp_v_open(struct atm_vcc *vcc)
  97. {
  98. struct atmtcp_control msg;
  99. int error;
  100. short vpi = vcc->vpi;
  101. int vci = vcc->vci;
  102. memset(&msg,0,sizeof(msg));
  103. msg.addr.sap_family = AF_ATMPVC;
  104. msg.hdr.vpi = htons(vpi);
  105. msg.addr.sap_addr.vpi = vpi;
  106. msg.hdr.vci = htons(vci);
  107. msg.addr.sap_addr.vci = vci;
  108. if (vpi == ATM_VPI_UNSPEC || vci == ATM_VCI_UNSPEC) return 0;
  109. msg.type = ATMTCP_CTRL_OPEN;
  110. msg.qos = vcc->qos;
  111. set_bit(ATM_VF_ADDR,&vcc->flags);
  112. clear_bit(ATM_VF_READY,&vcc->flags); /* just in case ... */
  113. error = atmtcp_send_control(vcc,ATMTCP_CTRL_OPEN,&msg,ATM_VF_READY);
  114. if (error) return error;
  115. return -sk_atm(vcc)->sk_err;
  116. }
  117. static void atmtcp_v_close(struct atm_vcc *vcc)
  118. {
  119. struct atmtcp_control msg;
  120. memset(&msg,0,sizeof(msg));
  121. msg.addr.sap_family = AF_ATMPVC;
  122. msg.addr.sap_addr.vpi = vcc->vpi;
  123. msg.addr.sap_addr.vci = vcc->vci;
  124. clear_bit(ATM_VF_READY,&vcc->flags);
  125. (void) atmtcp_send_control(vcc,ATMTCP_CTRL_CLOSE,&msg,ATM_VF_ADDR);
  126. }
  127. static int atmtcp_v_ioctl(struct atm_dev *dev,unsigned int cmd,void __user *arg)
  128. {
  129. struct atm_cirange ci;
  130. struct atm_vcc *vcc;
  131. struct sock *s;
  132. int i;
  133. if (cmd != ATM_SETCIRANGE) return -ENOIOCTLCMD;
  134. if (copy_from_user(&ci, arg,sizeof(ci))) return -EFAULT;
  135. if (ci.vpi_bits == ATM_CI_MAX) ci.vpi_bits = MAX_VPI_BITS;
  136. if (ci.vci_bits == ATM_CI_MAX) ci.vci_bits = MAX_VCI_BITS;
  137. if (ci.vpi_bits > MAX_VPI_BITS || ci.vpi_bits < 0 ||
  138. ci.vci_bits > MAX_VCI_BITS || ci.vci_bits < 0) return -EINVAL;
  139. read_lock(&vcc_sklist_lock);
  140. for(i = 0; i < VCC_HTABLE_SIZE; ++i) {
  141. struct hlist_head *head = &vcc_hash[i];
  142. sk_for_each(s, head) {
  143. vcc = atm_sk(s);
  144. if (vcc->dev != dev)
  145. continue;
  146. if ((vcc->vpi >> ci.vpi_bits) ||
  147. (vcc->vci >> ci.vci_bits)) {
  148. read_unlock(&vcc_sklist_lock);
  149. return -EBUSY;
  150. }
  151. }
  152. }
  153. read_unlock(&vcc_sklist_lock);
  154. dev->ci_range = ci;
  155. return 0;
  156. }
  157. static int atmtcp_v_send(struct atm_vcc *vcc,struct sk_buff *skb)
  158. {
  159. struct atmtcp_dev_data *dev_data;
  160. struct atm_vcc *out_vcc=NULL; /* Initializer quietens GCC warning */
  161. struct sk_buff *new_skb;
  162. struct atmtcp_hdr *hdr;
  163. int size;
  164. if (vcc->qos.txtp.traffic_class == ATM_NONE) {
  165. if (vcc->pop) vcc->pop(vcc,skb);
  166. else dev_kfree_skb(skb);
  167. return -EINVAL;
  168. }
  169. dev_data = PRIV(vcc->dev);
  170. if (dev_data) out_vcc = dev_data->vcc;
  171. if (!dev_data || !out_vcc) {
  172. if (vcc->pop) vcc->pop(vcc,skb);
  173. else dev_kfree_skb(skb);
  174. if (dev_data) return 0;
  175. atomic_inc(&vcc->stats->tx_err);
  176. return -ENOLINK;
  177. }
  178. size = skb->len+sizeof(struct atmtcp_hdr);
  179. new_skb = atm_alloc_charge(out_vcc,size,GFP_ATOMIC);
  180. if (!new_skb) {
  181. if (vcc->pop) vcc->pop(vcc,skb);
  182. else dev_kfree_skb(skb);
  183. atomic_inc(&vcc->stats->tx_err);
  184. return -ENOBUFS;
  185. }
  186. hdr = skb_put(new_skb, sizeof(struct atmtcp_hdr));
  187. hdr->vpi = htons(vcc->vpi);
  188. hdr->vci = htons(vcc->vci);
  189. hdr->length = htonl(skb->len);
  190. skb_copy_from_linear_data(skb, skb_put(new_skb, skb->len), skb->len);
  191. if (vcc->pop) vcc->pop(vcc,skb);
  192. else dev_kfree_skb(skb);
  193. out_vcc->push(out_vcc,new_skb);
  194. atomic_inc(&vcc->stats->tx);
  195. atomic_inc(&out_vcc->stats->rx);
  196. return 0;
  197. }
  198. static int atmtcp_v_proc(struct atm_dev *dev,loff_t *pos,char *page)
  199. {
  200. struct atmtcp_dev_data *dev_data = PRIV(dev);
  201. if (*pos) return 0;
  202. if (!dev_data->persist) return sprintf(page,"ephemeral\n");
  203. return sprintf(page,"persistent, %sconnected\n",
  204. dev_data->vcc ? "" : "dis");
  205. }
  206. static void atmtcp_c_close(struct atm_vcc *vcc)
  207. {
  208. struct atm_dev *atmtcp_dev;
  209. struct atmtcp_dev_data *dev_data;
  210. atmtcp_dev = (struct atm_dev *) vcc->dev_data;
  211. dev_data = PRIV(atmtcp_dev);
  212. dev_data->vcc = NULL;
  213. if (dev_data->persist) return;
  214. atmtcp_dev->dev_data = NULL;
  215. kfree(dev_data);
  216. atm_dev_deregister(atmtcp_dev);
  217. vcc->dev_data = NULL;
  218. module_put(THIS_MODULE);
  219. }
  220. static struct atm_vcc *find_vcc(struct atm_dev *dev, short vpi, int vci)
  221. {
  222. struct hlist_head *head;
  223. struct atm_vcc *vcc;
  224. struct sock *s;
  225. head = &vcc_hash[vci & (VCC_HTABLE_SIZE -1)];
  226. sk_for_each(s, head) {
  227. vcc = atm_sk(s);
  228. if (vcc->dev == dev &&
  229. vcc->vci == vci && vcc->vpi == vpi &&
  230. vcc->qos.rxtp.traffic_class != ATM_NONE) {
  231. return vcc;
  232. }
  233. }
  234. return NULL;
  235. }
  236. static int atmtcp_c_send(struct atm_vcc *vcc,struct sk_buff *skb)
  237. {
  238. struct atm_dev *dev;
  239. struct atmtcp_hdr *hdr;
  240. struct atm_vcc *out_vcc;
  241. struct sk_buff *new_skb;
  242. int result = 0;
  243. if (!skb->len) return 0;
  244. dev = vcc->dev_data;
  245. hdr = (struct atmtcp_hdr *) skb->data;
  246. if (hdr->length == ATMTCP_HDR_MAGIC) {
  247. result = atmtcp_recv_control(
  248. (struct atmtcp_control *) skb->data);
  249. goto done;
  250. }
  251. read_lock(&vcc_sklist_lock);
  252. out_vcc = find_vcc(dev, ntohs(hdr->vpi), ntohs(hdr->vci));
  253. read_unlock(&vcc_sklist_lock);
  254. if (!out_vcc) {
  255. result = -EUNATCH;
  256. atomic_inc(&vcc->stats->tx_err);
  257. goto done;
  258. }
  259. skb_pull(skb,sizeof(struct atmtcp_hdr));
  260. new_skb = atm_alloc_charge(out_vcc,skb->len,GFP_KERNEL);
  261. if (!new_skb) {
  262. result = -ENOBUFS;
  263. goto done;
  264. }
  265. __net_timestamp(new_skb);
  266. skb_copy_from_linear_data(skb, skb_put(new_skb, skb->len), skb->len);
  267. out_vcc->push(out_vcc,new_skb);
  268. atomic_inc(&vcc->stats->tx);
  269. atomic_inc(&out_vcc->stats->rx);
  270. done:
  271. if (vcc->pop) vcc->pop(vcc,skb);
  272. else dev_kfree_skb(skb);
  273. return result;
  274. }
  275. /*
  276. * Device operations for the virtual ATM devices created by ATMTCP.
  277. */
  278. static const struct atmdev_ops atmtcp_v_dev_ops = {
  279. .dev_close = atmtcp_v_dev_close,
  280. .open = atmtcp_v_open,
  281. .close = atmtcp_v_close,
  282. .ioctl = atmtcp_v_ioctl,
  283. .send = atmtcp_v_send,
  284. .proc_read = atmtcp_v_proc,
  285. .owner = THIS_MODULE
  286. };
  287. /*
  288. * Device operations for the ATMTCP control device.
  289. */
  290. static const struct atmdev_ops atmtcp_c_dev_ops = {
  291. .close = atmtcp_c_close,
  292. .send = atmtcp_c_send
  293. };
  294. static struct atm_dev atmtcp_control_dev = {
  295. .ops = &atmtcp_c_dev_ops,
  296. .type = "atmtcp",
  297. .number = 999,
  298. .lock = __SPIN_LOCK_UNLOCKED(atmtcp_control_dev.lock)
  299. };
  300. static int atmtcp_create(int itf,int persist,struct atm_dev **result)
  301. {
  302. struct atmtcp_dev_data *dev_data;
  303. struct atm_dev *dev;
  304. dev_data = kmalloc(sizeof(*dev_data),GFP_KERNEL);
  305. if (!dev_data)
  306. return -ENOMEM;
  307. dev = atm_dev_register(DEV_LABEL,NULL,&atmtcp_v_dev_ops,itf,NULL);
  308. if (!dev) {
  309. kfree(dev_data);
  310. return itf == -1 ? -ENOMEM : -EBUSY;
  311. }
  312. dev->ci_range.vpi_bits = MAX_VPI_BITS;
  313. dev->ci_range.vci_bits = MAX_VCI_BITS;
  314. dev->dev_data = dev_data;
  315. PRIV(dev)->vcc = NULL;
  316. PRIV(dev)->persist = persist;
  317. if (result) *result = dev;
  318. return 0;
  319. }
  320. static int atmtcp_attach(struct atm_vcc *vcc,int itf)
  321. {
  322. struct atm_dev *dev;
  323. dev = NULL;
  324. if (itf != -1) dev = atm_dev_lookup(itf);
  325. if (dev) {
  326. if (dev->ops != &atmtcp_v_dev_ops) {
  327. atm_dev_put(dev);
  328. return -EMEDIUMTYPE;
  329. }
  330. if (PRIV(dev)->vcc) {
  331. atm_dev_put(dev);
  332. return -EBUSY;
  333. }
  334. }
  335. else {
  336. int error;
  337. error = atmtcp_create(itf,0,&dev);
  338. if (error) return error;
  339. }
  340. PRIV(dev)->vcc = vcc;
  341. vcc->dev = &atmtcp_control_dev;
  342. vcc_insert_socket(sk_atm(vcc));
  343. set_bit(ATM_VF_META,&vcc->flags);
  344. set_bit(ATM_VF_READY,&vcc->flags);
  345. vcc->dev_data = dev;
  346. (void) atm_init_aal5(vcc); /* @@@ losing AAL in transit ... */
  347. vcc->stats = &atmtcp_control_dev.stats.aal5;
  348. return dev->number;
  349. }
  350. static int atmtcp_create_persistent(int itf)
  351. {
  352. return atmtcp_create(itf,1,NULL);
  353. }
  354. static int atmtcp_remove_persistent(int itf)
  355. {
  356. struct atm_dev *dev;
  357. struct atmtcp_dev_data *dev_data;
  358. dev = atm_dev_lookup(itf);
  359. if (!dev) return -ENODEV;
  360. if (dev->ops != &atmtcp_v_dev_ops) {
  361. atm_dev_put(dev);
  362. return -EMEDIUMTYPE;
  363. }
  364. dev_data = PRIV(dev);
  365. if (!dev_data->persist) {
  366. atm_dev_put(dev);
  367. return 0;
  368. }
  369. dev_data->persist = 0;
  370. if (PRIV(dev)->vcc) {
  371. atm_dev_put(dev);
  372. return 0;
  373. }
  374. kfree(dev_data);
  375. atm_dev_put(dev);
  376. atm_dev_deregister(dev);
  377. return 0;
  378. }
  379. static int atmtcp_ioctl(struct socket *sock, unsigned int cmd, unsigned long arg)
  380. {
  381. int err = 0;
  382. struct atm_vcc *vcc = ATM_SD(sock);
  383. if (cmd != SIOCSIFATMTCP && cmd != ATMTCP_CREATE && cmd != ATMTCP_REMOVE)
  384. return -ENOIOCTLCMD;
  385. if (!capable(CAP_NET_ADMIN))
  386. return -EPERM;
  387. switch (cmd) {
  388. case SIOCSIFATMTCP:
  389. err = atmtcp_attach(vcc, (int) arg);
  390. if (err >= 0) {
  391. sock->state = SS_CONNECTED;
  392. __module_get(THIS_MODULE);
  393. }
  394. break;
  395. case ATMTCP_CREATE:
  396. err = atmtcp_create_persistent((int) arg);
  397. break;
  398. case ATMTCP_REMOVE:
  399. err = atmtcp_remove_persistent((int) arg);
  400. break;
  401. }
  402. return err;
  403. }
  404. static struct atm_ioctl atmtcp_ioctl_ops = {
  405. .owner = THIS_MODULE,
  406. .ioctl = atmtcp_ioctl,
  407. };
  408. static __init int atmtcp_init(void)
  409. {
  410. register_atm_ioctl(&atmtcp_ioctl_ops);
  411. return 0;
  412. }
  413. static void __exit atmtcp_exit(void)
  414. {
  415. deregister_atm_ioctl(&atmtcp_ioctl_ops);
  416. }
  417. MODULE_LICENSE("GPL");
  418. module_init(atmtcp_init);
  419. module_exit(atmtcp_exit);