netpoll.c 19 KB

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  1. /*
  2. * Common framework for low-level network console, dump, and debugger code
  3. *
  4. * Sep 8 2003 Matt Mackall <mpm@selenic.com>
  5. *
  6. * based on the netconsole code from:
  7. *
  8. * Copyright (C) 2001 Ingo Molnar <mingo@redhat.com>
  9. * Copyright (C) 2002 Red Hat, Inc.
  10. */
  11. #include <linux/smp_lock.h>
  12. #include <linux/netdevice.h>
  13. #include <linux/etherdevice.h>
  14. #include <linux/string.h>
  15. #include <linux/if_arp.h>
  16. #include <linux/inetdevice.h>
  17. #include <linux/inet.h>
  18. #include <linux/interrupt.h>
  19. #include <linux/netpoll.h>
  20. #include <linux/sched.h>
  21. #include <linux/delay.h>
  22. #include <linux/rcupdate.h>
  23. #include <linux/workqueue.h>
  24. #include <net/tcp.h>
  25. #include <net/udp.h>
  26. #include <asm/unaligned.h>
  27. /*
  28. * We maintain a small pool of fully-sized skbs, to make sure the
  29. * message gets out even in extreme OOM situations.
  30. */
  31. #define MAX_UDP_CHUNK 1460
  32. #define MAX_SKBS 32
  33. #define MAX_QUEUE_DEPTH (MAX_SKBS / 2)
  34. static struct sk_buff_head skb_pool;
  35. static atomic_t trapped;
  36. #define USEC_PER_POLL 50
  37. #define NETPOLL_RX_ENABLED 1
  38. #define NETPOLL_RX_DROP 2
  39. #define MAX_SKB_SIZE \
  40. (MAX_UDP_CHUNK + sizeof(struct udphdr) + \
  41. sizeof(struct iphdr) + sizeof(struct ethhdr))
  42. static void zap_completion_queue(void);
  43. static void arp_reply(struct sk_buff *skb);
  44. static void queue_process(struct work_struct *work)
  45. {
  46. struct netpoll_info *npinfo =
  47. container_of(work, struct netpoll_info, tx_work.work);
  48. struct sk_buff *skb;
  49. unsigned long flags;
  50. while ((skb = skb_dequeue(&npinfo->txq))) {
  51. struct net_device *dev = skb->dev;
  52. if (!netif_device_present(dev) || !netif_running(dev)) {
  53. __kfree_skb(skb);
  54. continue;
  55. }
  56. local_irq_save(flags);
  57. netif_tx_lock(dev);
  58. if (netif_queue_stopped(dev) ||
  59. dev->hard_start_xmit(skb, dev) != NETDEV_TX_OK) {
  60. skb_queue_head(&npinfo->txq, skb);
  61. netif_tx_unlock(dev);
  62. local_irq_restore(flags);
  63. schedule_delayed_work(&npinfo->tx_work, HZ/10);
  64. return;
  65. }
  66. netif_tx_unlock(dev);
  67. local_irq_restore(flags);
  68. }
  69. }
  70. static __sum16 checksum_udp(struct sk_buff *skb, struct udphdr *uh,
  71. unsigned short ulen, __be32 saddr, __be32 daddr)
  72. {
  73. __wsum psum;
  74. if (uh->check == 0 || skb->ip_summed == CHECKSUM_UNNECESSARY)
  75. return 0;
  76. psum = csum_tcpudp_nofold(saddr, daddr, ulen, IPPROTO_UDP, 0);
  77. if (skb->ip_summed == CHECKSUM_COMPLETE &&
  78. !csum_fold(csum_add(psum, skb->csum)))
  79. return 0;
  80. skb->csum = psum;
  81. return __skb_checksum_complete(skb);
  82. }
  83. /*
  84. * Check whether delayed processing was scheduled for our NIC. If so,
  85. * we attempt to grab the poll lock and use ->poll() to pump the card.
  86. * If this fails, either we've recursed in ->poll() or it's already
  87. * running on another CPU.
  88. *
  89. * Note: we don't mask interrupts with this lock because we're using
  90. * trylock here and interrupts are already disabled in the softirq
  91. * case. Further, we test the poll_owner to avoid recursion on UP
  92. * systems where the lock doesn't exist.
  93. *
  94. * In cases where there is bi-directional communications, reading only
  95. * one message at a time can lead to packets being dropped by the
  96. * network adapter, forcing superfluous retries and possibly timeouts.
  97. * Thus, we set our budget to greater than 1.
  98. */
  99. static void poll_napi(struct netpoll *np)
  100. {
  101. struct netpoll_info *npinfo = np->dev->npinfo;
  102. int budget = 16;
  103. if (test_bit(__LINK_STATE_RX_SCHED, &np->dev->state) &&
  104. npinfo->poll_owner != smp_processor_id() &&
  105. spin_trylock(&npinfo->poll_lock)) {
  106. npinfo->rx_flags |= NETPOLL_RX_DROP;
  107. atomic_inc(&trapped);
  108. np->dev->poll(np->dev, &budget);
  109. atomic_dec(&trapped);
  110. npinfo->rx_flags &= ~NETPOLL_RX_DROP;
  111. spin_unlock(&npinfo->poll_lock);
  112. }
  113. }
  114. static void service_arp_queue(struct netpoll_info *npi)
  115. {
  116. struct sk_buff *skb;
  117. if (unlikely(!npi))
  118. return;
  119. skb = skb_dequeue(&npi->arp_tx);
  120. while (skb != NULL) {
  121. arp_reply(skb);
  122. skb = skb_dequeue(&npi->arp_tx);
  123. }
  124. }
  125. void netpoll_poll(struct netpoll *np)
  126. {
  127. if (!np->dev || !netif_running(np->dev) || !np->dev->poll_controller)
  128. return;
  129. /* Process pending work on NIC */
  130. np->dev->poll_controller(np->dev);
  131. if (np->dev->poll)
  132. poll_napi(np);
  133. service_arp_queue(np->dev->npinfo);
  134. zap_completion_queue();
  135. }
  136. static void refill_skbs(void)
  137. {
  138. struct sk_buff *skb;
  139. unsigned long flags;
  140. spin_lock_irqsave(&skb_pool.lock, flags);
  141. while (skb_pool.qlen < MAX_SKBS) {
  142. skb = alloc_skb(MAX_SKB_SIZE, GFP_ATOMIC);
  143. if (!skb)
  144. break;
  145. __skb_queue_tail(&skb_pool, skb);
  146. }
  147. spin_unlock_irqrestore(&skb_pool.lock, flags);
  148. }
  149. static void zap_completion_queue(void)
  150. {
  151. unsigned long flags;
  152. struct softnet_data *sd = &get_cpu_var(softnet_data);
  153. if (sd->completion_queue) {
  154. struct sk_buff *clist;
  155. local_irq_save(flags);
  156. clist = sd->completion_queue;
  157. sd->completion_queue = NULL;
  158. local_irq_restore(flags);
  159. while (clist != NULL) {
  160. struct sk_buff *skb = clist;
  161. clist = clist->next;
  162. if (skb->destructor)
  163. dev_kfree_skb_any(skb); /* put this one back */
  164. else
  165. __kfree_skb(skb);
  166. }
  167. }
  168. put_cpu_var(softnet_data);
  169. }
  170. static struct sk_buff *find_skb(struct netpoll *np, int len, int reserve)
  171. {
  172. int count = 0;
  173. struct sk_buff *skb;
  174. zap_completion_queue();
  175. refill_skbs();
  176. repeat:
  177. skb = alloc_skb(len, GFP_ATOMIC);
  178. if (!skb)
  179. skb = skb_dequeue(&skb_pool);
  180. if (!skb) {
  181. if (++count < 10) {
  182. netpoll_poll(np);
  183. goto repeat;
  184. }
  185. return NULL;
  186. }
  187. atomic_set(&skb->users, 1);
  188. skb_reserve(skb, reserve);
  189. return skb;
  190. }
  191. static void netpoll_send_skb(struct netpoll *np, struct sk_buff *skb)
  192. {
  193. int status = NETDEV_TX_BUSY;
  194. unsigned long tries;
  195. struct net_device *dev = np->dev;
  196. struct netpoll_info *npinfo = np->dev->npinfo;
  197. if (!npinfo || !netif_running(dev) || !netif_device_present(dev)) {
  198. __kfree_skb(skb);
  199. return;
  200. }
  201. /* don't get messages out of order, and no recursion */
  202. if (skb_queue_len(&npinfo->txq) == 0 &&
  203. npinfo->poll_owner != smp_processor_id()) {
  204. unsigned long flags;
  205. local_irq_save(flags);
  206. if (netif_tx_trylock(dev)) {
  207. /* try until next clock tick */
  208. for (tries = jiffies_to_usecs(1)/USEC_PER_POLL;
  209. tries > 0; --tries) {
  210. if (!netif_queue_stopped(dev))
  211. status = dev->hard_start_xmit(skb, dev);
  212. if (status == NETDEV_TX_OK)
  213. break;
  214. /* tickle device maybe there is some cleanup */
  215. netpoll_poll(np);
  216. udelay(USEC_PER_POLL);
  217. }
  218. netif_tx_unlock(dev);
  219. }
  220. local_irq_restore(flags);
  221. }
  222. if (status != NETDEV_TX_OK) {
  223. skb_queue_tail(&npinfo->txq, skb);
  224. schedule_delayed_work(&npinfo->tx_work,0);
  225. }
  226. }
  227. void netpoll_send_udp(struct netpoll *np, const char *msg, int len)
  228. {
  229. int total_len, eth_len, ip_len, udp_len;
  230. struct sk_buff *skb;
  231. struct udphdr *udph;
  232. struct iphdr *iph;
  233. struct ethhdr *eth;
  234. udp_len = len + sizeof(*udph);
  235. ip_len = eth_len = udp_len + sizeof(*iph);
  236. total_len = eth_len + ETH_HLEN + NET_IP_ALIGN;
  237. skb = find_skb(np, total_len, total_len - len);
  238. if (!skb)
  239. return;
  240. memcpy(skb->data, msg, len);
  241. skb->len += len;
  242. skb->h.uh = udph = (struct udphdr *) skb_push(skb, sizeof(*udph));
  243. udph->source = htons(np->local_port);
  244. udph->dest = htons(np->remote_port);
  245. udph->len = htons(udp_len);
  246. udph->check = 0;
  247. udph->check = csum_tcpudp_magic(htonl(np->local_ip),
  248. htonl(np->remote_ip),
  249. udp_len, IPPROTO_UDP,
  250. csum_partial((unsigned char *)udph, udp_len, 0));
  251. if (udph->check == 0)
  252. udph->check = CSUM_MANGLED_0;
  253. skb->nh.iph = iph = (struct iphdr *)skb_push(skb, sizeof(*iph));
  254. /* iph->version = 4; iph->ihl = 5; */
  255. put_unaligned(0x45, (unsigned char *)iph);
  256. iph->tos = 0;
  257. put_unaligned(htons(ip_len), &(iph->tot_len));
  258. iph->id = 0;
  259. iph->frag_off = 0;
  260. iph->ttl = 64;
  261. iph->protocol = IPPROTO_UDP;
  262. iph->check = 0;
  263. put_unaligned(htonl(np->local_ip), &(iph->saddr));
  264. put_unaligned(htonl(np->remote_ip), &(iph->daddr));
  265. iph->check = ip_fast_csum((unsigned char *)iph, iph->ihl);
  266. eth = (struct ethhdr *) skb_push(skb, ETH_HLEN);
  267. skb->mac.raw = skb->data;
  268. skb->protocol = eth->h_proto = htons(ETH_P_IP);
  269. memcpy(eth->h_source, np->local_mac, 6);
  270. memcpy(eth->h_dest, np->remote_mac, 6);
  271. skb->dev = np->dev;
  272. netpoll_send_skb(np, skb);
  273. }
  274. static void arp_reply(struct sk_buff *skb)
  275. {
  276. struct netpoll_info *npinfo = skb->dev->npinfo;
  277. struct arphdr *arp;
  278. unsigned char *arp_ptr;
  279. int size, type = ARPOP_REPLY, ptype = ETH_P_ARP;
  280. __be32 sip, tip;
  281. unsigned char *sha;
  282. struct sk_buff *send_skb;
  283. struct netpoll *np = NULL;
  284. if (npinfo->rx_np && npinfo->rx_np->dev == skb->dev)
  285. np = npinfo->rx_np;
  286. if (!np)
  287. return;
  288. /* No arp on this interface */
  289. if (skb->dev->flags & IFF_NOARP)
  290. return;
  291. if (!pskb_may_pull(skb, (sizeof(struct arphdr) +
  292. (2 * skb->dev->addr_len) +
  293. (2 * sizeof(u32)))))
  294. return;
  295. skb->h.raw = skb->nh.raw = skb->data;
  296. arp = skb->nh.arph;
  297. if ((arp->ar_hrd != htons(ARPHRD_ETHER) &&
  298. arp->ar_hrd != htons(ARPHRD_IEEE802)) ||
  299. arp->ar_pro != htons(ETH_P_IP) ||
  300. arp->ar_op != htons(ARPOP_REQUEST))
  301. return;
  302. arp_ptr = (unsigned char *)(arp+1);
  303. /* save the location of the src hw addr */
  304. sha = arp_ptr;
  305. arp_ptr += skb->dev->addr_len;
  306. memcpy(&sip, arp_ptr, 4);
  307. arp_ptr += 4;
  308. /* if we actually cared about dst hw addr, it would get copied here */
  309. arp_ptr += skb->dev->addr_len;
  310. memcpy(&tip, arp_ptr, 4);
  311. /* Should we ignore arp? */
  312. if (tip != htonl(np->local_ip) || LOOPBACK(tip) || MULTICAST(tip))
  313. return;
  314. size = sizeof(struct arphdr) + 2 * (skb->dev->addr_len + 4);
  315. send_skb = find_skb(np, size + LL_RESERVED_SPACE(np->dev),
  316. LL_RESERVED_SPACE(np->dev));
  317. if (!send_skb)
  318. return;
  319. send_skb->nh.raw = send_skb->data;
  320. arp = (struct arphdr *) skb_put(send_skb, size);
  321. send_skb->dev = skb->dev;
  322. send_skb->protocol = htons(ETH_P_ARP);
  323. /* Fill the device header for the ARP frame */
  324. if (np->dev->hard_header &&
  325. np->dev->hard_header(send_skb, skb->dev, ptype,
  326. sha, np->local_mac,
  327. send_skb->len) < 0) {
  328. kfree_skb(send_skb);
  329. return;
  330. }
  331. /*
  332. * Fill out the arp protocol part.
  333. *
  334. * we only support ethernet device type,
  335. * which (according to RFC 1390) should always equal 1 (Ethernet).
  336. */
  337. arp->ar_hrd = htons(np->dev->type);
  338. arp->ar_pro = htons(ETH_P_IP);
  339. arp->ar_hln = np->dev->addr_len;
  340. arp->ar_pln = 4;
  341. arp->ar_op = htons(type);
  342. arp_ptr=(unsigned char *)(arp + 1);
  343. memcpy(arp_ptr, np->dev->dev_addr, np->dev->addr_len);
  344. arp_ptr += np->dev->addr_len;
  345. memcpy(arp_ptr, &tip, 4);
  346. arp_ptr += 4;
  347. memcpy(arp_ptr, sha, np->dev->addr_len);
  348. arp_ptr += np->dev->addr_len;
  349. memcpy(arp_ptr, &sip, 4);
  350. netpoll_send_skb(np, send_skb);
  351. }
  352. int __netpoll_rx(struct sk_buff *skb)
  353. {
  354. int proto, len, ulen;
  355. struct iphdr *iph;
  356. struct udphdr *uh;
  357. struct netpoll_info *npi = skb->dev->npinfo;
  358. struct netpoll *np = npi->rx_np;
  359. if (!np)
  360. goto out;
  361. if (skb->dev->type != ARPHRD_ETHER)
  362. goto out;
  363. /* check if netpoll clients need ARP */
  364. if (skb->protocol == __constant_htons(ETH_P_ARP) &&
  365. atomic_read(&trapped)) {
  366. skb_queue_tail(&npi->arp_tx, skb);
  367. return 1;
  368. }
  369. proto = ntohs(eth_hdr(skb)->h_proto);
  370. if (proto != ETH_P_IP)
  371. goto out;
  372. if (skb->pkt_type == PACKET_OTHERHOST)
  373. goto out;
  374. if (skb_shared(skb))
  375. goto out;
  376. iph = (struct iphdr *)skb->data;
  377. if (!pskb_may_pull(skb, sizeof(struct iphdr)))
  378. goto out;
  379. if (iph->ihl < 5 || iph->version != 4)
  380. goto out;
  381. if (!pskb_may_pull(skb, iph->ihl*4))
  382. goto out;
  383. if (ip_fast_csum((u8 *)iph, iph->ihl) != 0)
  384. goto out;
  385. len = ntohs(iph->tot_len);
  386. if (skb->len < len || len < iph->ihl*4)
  387. goto out;
  388. /*
  389. * Our transport medium may have padded the buffer out.
  390. * Now We trim to the true length of the frame.
  391. */
  392. if (pskb_trim_rcsum(skb, len))
  393. goto out;
  394. if (iph->protocol != IPPROTO_UDP)
  395. goto out;
  396. len -= iph->ihl*4;
  397. uh = (struct udphdr *)(((char *)iph) + iph->ihl*4);
  398. ulen = ntohs(uh->len);
  399. if (ulen != len)
  400. goto out;
  401. if (checksum_udp(skb, uh, ulen, iph->saddr, iph->daddr))
  402. goto out;
  403. if (np->local_ip && np->local_ip != ntohl(iph->daddr))
  404. goto out;
  405. if (np->remote_ip && np->remote_ip != ntohl(iph->saddr))
  406. goto out;
  407. if (np->local_port && np->local_port != ntohs(uh->dest))
  408. goto out;
  409. np->rx_hook(np, ntohs(uh->source),
  410. (char *)(uh+1),
  411. ulen - sizeof(struct udphdr));
  412. kfree_skb(skb);
  413. return 1;
  414. out:
  415. if (atomic_read(&trapped)) {
  416. kfree_skb(skb);
  417. return 1;
  418. }
  419. return 0;
  420. }
  421. int netpoll_parse_options(struct netpoll *np, char *opt)
  422. {
  423. char *cur=opt, *delim;
  424. if (*cur != '@') {
  425. if ((delim = strchr(cur, '@')) == NULL)
  426. goto parse_failed;
  427. *delim = 0;
  428. np->local_port = simple_strtol(cur, NULL, 10);
  429. cur = delim;
  430. }
  431. cur++;
  432. printk(KERN_INFO "%s: local port %d\n", np->name, np->local_port);
  433. if (*cur != '/') {
  434. if ((delim = strchr(cur, '/')) == NULL)
  435. goto parse_failed;
  436. *delim = 0;
  437. np->local_ip = ntohl(in_aton(cur));
  438. cur = delim;
  439. printk(KERN_INFO "%s: local IP %d.%d.%d.%d\n",
  440. np->name, HIPQUAD(np->local_ip));
  441. }
  442. cur++;
  443. if (*cur != ',') {
  444. /* parse out dev name */
  445. if ((delim = strchr(cur, ',')) == NULL)
  446. goto parse_failed;
  447. *delim = 0;
  448. strlcpy(np->dev_name, cur, sizeof(np->dev_name));
  449. cur = delim;
  450. }
  451. cur++;
  452. printk(KERN_INFO "%s: interface %s\n", np->name, np->dev_name);
  453. if (*cur != '@') {
  454. /* dst port */
  455. if ((delim = strchr(cur, '@')) == NULL)
  456. goto parse_failed;
  457. *delim = 0;
  458. np->remote_port = simple_strtol(cur, NULL, 10);
  459. cur = delim;
  460. }
  461. cur++;
  462. printk(KERN_INFO "%s: remote port %d\n", np->name, np->remote_port);
  463. /* dst ip */
  464. if ((delim = strchr(cur, '/')) == NULL)
  465. goto parse_failed;
  466. *delim = 0;
  467. np->remote_ip = ntohl(in_aton(cur));
  468. cur = delim + 1;
  469. printk(KERN_INFO "%s: remote IP %d.%d.%d.%d\n",
  470. np->name, HIPQUAD(np->remote_ip));
  471. if (*cur != 0) {
  472. /* MAC address */
  473. if ((delim = strchr(cur, ':')) == NULL)
  474. goto parse_failed;
  475. *delim = 0;
  476. np->remote_mac[0] = simple_strtol(cur, NULL, 16);
  477. cur = delim + 1;
  478. if ((delim = strchr(cur, ':')) == NULL)
  479. goto parse_failed;
  480. *delim = 0;
  481. np->remote_mac[1] = simple_strtol(cur, NULL, 16);
  482. cur = delim + 1;
  483. if ((delim = strchr(cur, ':')) == NULL)
  484. goto parse_failed;
  485. *delim = 0;
  486. np->remote_mac[2] = simple_strtol(cur, NULL, 16);
  487. cur = delim + 1;
  488. if ((delim = strchr(cur, ':')) == NULL)
  489. goto parse_failed;
  490. *delim = 0;
  491. np->remote_mac[3] = simple_strtol(cur, NULL, 16);
  492. cur = delim + 1;
  493. if ((delim = strchr(cur, ':')) == NULL)
  494. goto parse_failed;
  495. *delim = 0;
  496. np->remote_mac[4] = simple_strtol(cur, NULL, 16);
  497. cur = delim + 1;
  498. np->remote_mac[5] = simple_strtol(cur, NULL, 16);
  499. }
  500. printk(KERN_INFO "%s: remote ethernet address "
  501. "%02x:%02x:%02x:%02x:%02x:%02x\n",
  502. np->name,
  503. np->remote_mac[0],
  504. np->remote_mac[1],
  505. np->remote_mac[2],
  506. np->remote_mac[3],
  507. np->remote_mac[4],
  508. np->remote_mac[5]);
  509. return 0;
  510. parse_failed:
  511. printk(KERN_INFO "%s: couldn't parse config at %s!\n",
  512. np->name, cur);
  513. return -1;
  514. }
  515. int netpoll_setup(struct netpoll *np)
  516. {
  517. struct net_device *ndev = NULL;
  518. struct in_device *in_dev;
  519. struct netpoll_info *npinfo;
  520. unsigned long flags;
  521. int err;
  522. if (np->dev_name)
  523. ndev = dev_get_by_name(np->dev_name);
  524. if (!ndev) {
  525. printk(KERN_ERR "%s: %s doesn't exist, aborting.\n",
  526. np->name, np->dev_name);
  527. return -ENODEV;
  528. }
  529. np->dev = ndev;
  530. if (!ndev->npinfo) {
  531. npinfo = kmalloc(sizeof(*npinfo), GFP_KERNEL);
  532. if (!npinfo) {
  533. err = -ENOMEM;
  534. goto release;
  535. }
  536. npinfo->rx_flags = 0;
  537. npinfo->rx_np = NULL;
  538. spin_lock_init(&npinfo->poll_lock);
  539. npinfo->poll_owner = -1;
  540. spin_lock_init(&npinfo->rx_lock);
  541. skb_queue_head_init(&npinfo->arp_tx);
  542. skb_queue_head_init(&npinfo->txq);
  543. INIT_DELAYED_WORK(&npinfo->tx_work, queue_process);
  544. atomic_set(&npinfo->refcnt, 1);
  545. } else {
  546. npinfo = ndev->npinfo;
  547. atomic_inc(&npinfo->refcnt);
  548. }
  549. if (!ndev->poll_controller) {
  550. printk(KERN_ERR "%s: %s doesn't support polling, aborting.\n",
  551. np->name, np->dev_name);
  552. err = -ENOTSUPP;
  553. goto release;
  554. }
  555. if (!netif_running(ndev)) {
  556. unsigned long atmost, atleast;
  557. printk(KERN_INFO "%s: device %s not up yet, forcing it\n",
  558. np->name, np->dev_name);
  559. rtnl_lock();
  560. err = dev_open(ndev);
  561. rtnl_unlock();
  562. if (err) {
  563. printk(KERN_ERR "%s: failed to open %s\n",
  564. np->name, ndev->name);
  565. goto release;
  566. }
  567. atleast = jiffies + HZ/10;
  568. atmost = jiffies + 4*HZ;
  569. while (!netif_carrier_ok(ndev)) {
  570. if (time_after(jiffies, atmost)) {
  571. printk(KERN_NOTICE
  572. "%s: timeout waiting for carrier\n",
  573. np->name);
  574. break;
  575. }
  576. cond_resched();
  577. }
  578. /* If carrier appears to come up instantly, we don't
  579. * trust it and pause so that we don't pump all our
  580. * queued console messages into the bitbucket.
  581. */
  582. if (time_before(jiffies, atleast)) {
  583. printk(KERN_NOTICE "%s: carrier detect appears"
  584. " untrustworthy, waiting 4 seconds\n",
  585. np->name);
  586. msleep(4000);
  587. }
  588. }
  589. if (is_zero_ether_addr(np->local_mac) && ndev->dev_addr)
  590. memcpy(np->local_mac, ndev->dev_addr, 6);
  591. if (!np->local_ip) {
  592. rcu_read_lock();
  593. in_dev = __in_dev_get_rcu(ndev);
  594. if (!in_dev || !in_dev->ifa_list) {
  595. rcu_read_unlock();
  596. printk(KERN_ERR "%s: no IP address for %s, aborting\n",
  597. np->name, np->dev_name);
  598. err = -EDESTADDRREQ;
  599. goto release;
  600. }
  601. np->local_ip = ntohl(in_dev->ifa_list->ifa_local);
  602. rcu_read_unlock();
  603. printk(KERN_INFO "%s: local IP %d.%d.%d.%d\n",
  604. np->name, HIPQUAD(np->local_ip));
  605. }
  606. if (np->rx_hook) {
  607. spin_lock_irqsave(&npinfo->rx_lock, flags);
  608. npinfo->rx_flags |= NETPOLL_RX_ENABLED;
  609. npinfo->rx_np = np;
  610. spin_unlock_irqrestore(&npinfo->rx_lock, flags);
  611. }
  612. /* fill up the skb queue */
  613. refill_skbs();
  614. /* last thing to do is link it to the net device structure */
  615. ndev->npinfo = npinfo;
  616. /* avoid racing with NAPI reading npinfo */
  617. synchronize_rcu();
  618. return 0;
  619. release:
  620. if (!ndev->npinfo)
  621. kfree(npinfo);
  622. np->dev = NULL;
  623. dev_put(ndev);
  624. return err;
  625. }
  626. static int __init netpoll_init(void)
  627. {
  628. skb_queue_head_init(&skb_pool);
  629. return 0;
  630. }
  631. core_initcall(netpoll_init);
  632. void netpoll_cleanup(struct netpoll *np)
  633. {
  634. struct netpoll_info *npinfo;
  635. unsigned long flags;
  636. if (np->dev) {
  637. npinfo = np->dev->npinfo;
  638. if (npinfo) {
  639. if (npinfo->rx_np == np) {
  640. spin_lock_irqsave(&npinfo->rx_lock, flags);
  641. npinfo->rx_np = NULL;
  642. npinfo->rx_flags &= ~NETPOLL_RX_ENABLED;
  643. spin_unlock_irqrestore(&npinfo->rx_lock, flags);
  644. }
  645. np->dev->npinfo = NULL;
  646. if (atomic_dec_and_test(&npinfo->refcnt)) {
  647. skb_queue_purge(&npinfo->arp_tx);
  648. skb_queue_purge(&npinfo->txq);
  649. cancel_rearming_delayed_work(&npinfo->tx_work);
  650. flush_scheduled_work();
  651. kfree(npinfo);
  652. }
  653. }
  654. dev_put(np->dev);
  655. }
  656. np->dev = NULL;
  657. }
  658. int netpoll_trap(void)
  659. {
  660. return atomic_read(&trapped);
  661. }
  662. void netpoll_set_trap(int trap)
  663. {
  664. if (trap)
  665. atomic_inc(&trapped);
  666. else
  667. atomic_dec(&trapped);
  668. }
  669. EXPORT_SYMBOL(netpoll_set_trap);
  670. EXPORT_SYMBOL(netpoll_trap);
  671. EXPORT_SYMBOL(netpoll_parse_options);
  672. EXPORT_SYMBOL(netpoll_setup);
  673. EXPORT_SYMBOL(netpoll_cleanup);
  674. EXPORT_SYMBOL(netpoll_send_udp);
  675. EXPORT_SYMBOL(netpoll_poll);