~ [ source navigation ] ~ [ diff markup ] ~ [ identifier search ] ~

TOMOYO Linux Cross Reference
Linux/net/core/netpoll.c

Version: ~ [ linux-5.12-rc1 ] ~ [ linux-5.11.2 ] ~ [ linux-5.10.19 ] ~ [ linux-5.9.16 ] ~ [ linux-5.8.18 ] ~ [ linux-5.7.19 ] ~ [ linux-5.6.19 ] ~ [ linux-5.5.19 ] ~ [ linux-5.4.101 ] ~ [ linux-5.3.18 ] ~ [ linux-5.2.21 ] ~ [ linux-5.1.21 ] ~ [ linux-5.0.21 ] ~ [ linux-4.20.17 ] ~ [ linux-4.19.177 ] ~ [ linux-4.18.20 ] ~ [ linux-4.17.19 ] ~ [ linux-4.16.18 ] ~ [ linux-4.15.18 ] ~ [ linux-4.14.222 ] ~ [ linux-4.13.16 ] ~ [ linux-4.12.14 ] ~ [ linux-4.11.12 ] ~ [ linux-4.10.17 ] ~ [ linux-4.9.258 ] ~ [ linux-4.8.17 ] ~ [ linux-4.7.10 ] ~ [ linux-4.6.7 ] ~ [ linux-4.5.7 ] ~ [ linux-4.4.258 ] ~ [ linux-4.3.6 ] ~ [ linux-4.2.8 ] ~ [ linux-4.1.52 ] ~ [ linux-4.0.9 ] ~ [ linux-3.18.140 ] ~ [ linux-3.16.85 ] ~ [ linux-3.14.79 ] ~ [ linux-3.12.74 ] ~ [ linux-3.10.108 ] ~ [ linux-2.6.32.71 ] ~ [ linux-2.6.0 ] ~ [ linux-2.4.37.11 ] ~ [ unix-v6-master ] ~ [ ccs-tools-1.8.5 ] ~ [ policy-sample ] ~
Architecture: ~ [ i386 ] ~ [ alpha ] ~ [ m68k ] ~ [ mips ] ~ [ ppc ] ~ [ sparc ] ~ [ sparc64 ] ~

  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 
 12 #define pr_fmt(fmt) KBUILD_MODNAME ": " fmt
 13 
 14 #include <linux/moduleparam.h>
 15 #include <linux/kernel.h>
 16 #include <linux/netdevice.h>
 17 #include <linux/etherdevice.h>
 18 #include <linux/string.h>
 19 #include <linux/if_arp.h>
 20 #include <linux/inetdevice.h>
 21 #include <linux/inet.h>
 22 #include <linux/interrupt.h>
 23 #include <linux/netpoll.h>
 24 #include <linux/sched.h>
 25 #include <linux/delay.h>
 26 #include <linux/rcupdate.h>
 27 #include <linux/workqueue.h>
 28 #include <linux/slab.h>
 29 #include <linux/export.h>
 30 #include <linux/if_vlan.h>
 31 #include <net/tcp.h>
 32 #include <net/udp.h>
 33 #include <net/addrconf.h>
 34 #include <net/ndisc.h>
 35 #include <net/ip6_checksum.h>
 36 #include <asm/unaligned.h>
 37 #include <trace/events/napi.h>
 38 
 39 /*
 40  * We maintain a small pool of fully-sized skbs, to make sure the
 41  * message gets out even in extreme OOM situations.
 42  */
 43 
 44 #define MAX_UDP_CHUNK 1460
 45 #define MAX_SKBS 32
 46 
 47 static struct sk_buff_head skb_pool;
 48 
 49 DEFINE_STATIC_SRCU(netpoll_srcu);
 50 
 51 #define USEC_PER_POLL   50
 52 
 53 #define MAX_SKB_SIZE                                                    \
 54         (sizeof(struct ethhdr) +                                        \
 55          sizeof(struct iphdr) +                                         \
 56          sizeof(struct udphdr) +                                        \
 57          MAX_UDP_CHUNK)
 58 
 59 static void zap_completion_queue(void);
 60 static void netpoll_async_cleanup(struct work_struct *work);
 61 
 62 static unsigned int carrier_timeout = 4;
 63 module_param(carrier_timeout, uint, 0644);
 64 
 65 #define np_info(np, fmt, ...)                           \
 66         pr_info("%s: " fmt, np->name, ##__VA_ARGS__)
 67 #define np_err(np, fmt, ...)                            \
 68         pr_err("%s: " fmt, np->name, ##__VA_ARGS__)
 69 #define np_notice(np, fmt, ...)                         \
 70         pr_notice("%s: " fmt, np->name, ##__VA_ARGS__)
 71 
 72 static int netpoll_start_xmit(struct sk_buff *skb, struct net_device *dev,
 73                               struct netdev_queue *txq)
 74 {
 75         int status = NETDEV_TX_OK;
 76         netdev_features_t features;
 77 
 78         features = netif_skb_features(skb);
 79 
 80         if (skb_vlan_tag_present(skb) &&
 81             !vlan_hw_offload_capable(features, skb->vlan_proto)) {
 82                 skb = __vlan_hwaccel_push_inside(skb);
 83                 if (unlikely(!skb)) {
 84                         /* This is actually a packet drop, but we
 85                          * don't want the code that calls this
 86                          * function to try and operate on a NULL skb.
 87                          */
 88                         goto out;
 89                 }
 90         }
 91 
 92         status = netdev_start_xmit(skb, dev, txq, false);
 93 
 94 out:
 95         return status;
 96 }
 97 
 98 static void queue_process(struct work_struct *work)
 99 {
100         struct netpoll_info *npinfo =
101                 container_of(work, struct netpoll_info, tx_work.work);
102         struct sk_buff *skb;
103         unsigned long flags;
104 
105         while ((skb = skb_dequeue(&npinfo->txq))) {
106                 struct net_device *dev = skb->dev;
107                 struct netdev_queue *txq;
108 
109                 if (!netif_device_present(dev) || !netif_running(dev)) {
110                         kfree_skb(skb);
111                         continue;
112                 }
113 
114                 txq = skb_get_tx_queue(dev, skb);
115 
116                 local_irq_save(flags);
117                 HARD_TX_LOCK(dev, txq, smp_processor_id());
118                 if (netif_xmit_frozen_or_stopped(txq) ||
119                     netpoll_start_xmit(skb, dev, txq) != NETDEV_TX_OK) {
120                         skb_queue_head(&npinfo->txq, skb);
121                         HARD_TX_UNLOCK(dev, txq);
122                         local_irq_restore(flags);
123 
124                         schedule_delayed_work(&npinfo->tx_work, HZ/10);
125                         return;
126                 }
127                 HARD_TX_UNLOCK(dev, txq);
128                 local_irq_restore(flags);
129         }
130 }
131 
132 /*
133  * Check whether delayed processing was scheduled for our NIC. If so,
134  * we attempt to grab the poll lock and use ->poll() to pump the card.
135  * If this fails, either we've recursed in ->poll() or it's already
136  * running on another CPU.
137  *
138  * Note: we don't mask interrupts with this lock because we're using
139  * trylock here and interrupts are already disabled in the softirq
140  * case. Further, we test the poll_owner to avoid recursion on UP
141  * systems where the lock doesn't exist.
142  */
143 static void poll_one_napi(struct napi_struct *napi)
144 {
145         int work = 0;
146 
147         /* net_rx_action's ->poll() invocations and our's are
148          * synchronized by this test which is only made while
149          * holding the napi->poll_lock.
150          */
151         if (!test_bit(NAPI_STATE_SCHED, &napi->state))
152                 return;
153 
154         /* If we set this bit but see that it has already been set,
155          * that indicates that napi has been disabled and we need
156          * to abort this operation
157          */
158         if (test_and_set_bit(NAPI_STATE_NPSVC, &napi->state))
159                 return;
160 
161         /* We explicilty pass the polling call a budget of 0 to
162          * indicate that we are clearing the Tx path only.
163          */
164         work = napi->poll(napi, 0);
165         WARN_ONCE(work, "%pF exceeded budget in poll\n", napi->poll);
166         trace_napi_poll(napi, work, 0);
167 
168         clear_bit(NAPI_STATE_NPSVC, &napi->state);
169 }
170 
171 static void poll_napi(struct net_device *dev)
172 {
173         struct napi_struct *napi;
174 
175         list_for_each_entry(napi, &dev->napi_list, dev_list) {
176                 if (napi->poll_owner != smp_processor_id() &&
177                     spin_trylock(&napi->poll_lock)) {
178                         poll_one_napi(napi);
179                         spin_unlock(&napi->poll_lock);
180                 }
181         }
182 }
183 
184 static void netpoll_poll_dev(struct net_device *dev)
185 {
186         const struct net_device_ops *ops;
187         struct netpoll_info *ni = rcu_dereference_bh(dev->npinfo);
188 
189         /* Don't do any rx activity if the dev_lock mutex is held
190          * the dev_open/close paths use this to block netpoll activity
191          * while changing device state
192          */
193         if (down_trylock(&ni->dev_lock))
194                 return;
195 
196         if (!netif_running(dev)) {
197                 up(&ni->dev_lock);
198                 return;
199         }
200 
201         ops = dev->netdev_ops;
202         if (!ops->ndo_poll_controller) {
203                 up(&ni->dev_lock);
204                 return;
205         }
206 
207         /* Process pending work on NIC */
208         ops->ndo_poll_controller(dev);
209 
210         poll_napi(dev);
211 
212         up(&ni->dev_lock);
213 
214         zap_completion_queue();
215 }
216 
217 void netpoll_poll_disable(struct net_device *dev)
218 {
219         struct netpoll_info *ni;
220         int idx;
221         might_sleep();
222         idx = srcu_read_lock(&netpoll_srcu);
223         ni = srcu_dereference(dev->npinfo, &netpoll_srcu);
224         if (ni)
225                 down(&ni->dev_lock);
226         srcu_read_unlock(&netpoll_srcu, idx);
227 }
228 EXPORT_SYMBOL(netpoll_poll_disable);
229 
230 void netpoll_poll_enable(struct net_device *dev)
231 {
232         struct netpoll_info *ni;
233         rcu_read_lock();
234         ni = rcu_dereference(dev->npinfo);
235         if (ni)
236                 up(&ni->dev_lock);
237         rcu_read_unlock();
238 }
239 EXPORT_SYMBOL(netpoll_poll_enable);
240 
241 static void refill_skbs(void)
242 {
243         struct sk_buff *skb;
244         unsigned long flags;
245 
246         spin_lock_irqsave(&skb_pool.lock, flags);
247         while (skb_pool.qlen < MAX_SKBS) {
248                 skb = alloc_skb(MAX_SKB_SIZE, GFP_ATOMIC);
249                 if (!skb)
250                         break;
251 
252                 __skb_queue_tail(&skb_pool, skb);
253         }
254         spin_unlock_irqrestore(&skb_pool.lock, flags);
255 }
256 
257 static void zap_completion_queue(void)
258 {
259         unsigned long flags;
260         struct softnet_data *sd = &get_cpu_var(softnet_data);
261 
262         if (sd->completion_queue) {
263                 struct sk_buff *clist;
264 
265                 local_irq_save(flags);
266                 clist = sd->completion_queue;
267                 sd->completion_queue = NULL;
268                 local_irq_restore(flags);
269 
270                 while (clist != NULL) {
271                         struct sk_buff *skb = clist;
272                         clist = clist->next;
273                         if (!skb_irq_freeable(skb)) {
274                                 atomic_inc(&skb->users);
275                                 dev_kfree_skb_any(skb); /* put this one back */
276                         } else {
277                                 __kfree_skb(skb);
278                         }
279                 }
280         }
281 
282         put_cpu_var(softnet_data);
283 }
284 
285 static struct sk_buff *find_skb(struct netpoll *np, int len, int reserve)
286 {
287         int count = 0;
288         struct sk_buff *skb;
289 
290         zap_completion_queue();
291         refill_skbs();
292 repeat:
293 
294         skb = alloc_skb(len, GFP_ATOMIC);
295         if (!skb)
296                 skb = skb_dequeue(&skb_pool);
297 
298         if (!skb) {
299                 if (++count < 10) {
300                         netpoll_poll_dev(np->dev);
301                         goto repeat;
302                 }
303                 return NULL;
304         }
305 
306         atomic_set(&skb->users, 1);
307         skb_reserve(skb, reserve);
308         return skb;
309 }
310 
311 static int netpoll_owner_active(struct net_device *dev)
312 {
313         struct napi_struct *napi;
314 
315         list_for_each_entry(napi, &dev->napi_list, dev_list) {
316                 if (napi->poll_owner == smp_processor_id())
317                         return 1;
318         }
319         return 0;
320 }
321 
322 /* call with IRQ disabled */
323 void netpoll_send_skb_on_dev(struct netpoll *np, struct sk_buff *skb,
324                              struct net_device *dev)
325 {
326         int status = NETDEV_TX_BUSY;
327         unsigned long tries;
328         /* It is up to the caller to keep npinfo alive. */
329         struct netpoll_info *npinfo;
330 
331         WARN_ON_ONCE(!irqs_disabled());
332 
333         npinfo = rcu_dereference_bh(np->dev->npinfo);
334         if (!npinfo || !netif_running(dev) || !netif_device_present(dev)) {
335                 dev_kfree_skb_irq(skb);
336                 return;
337         }
338 
339         /* don't get messages out of order, and no recursion */
340         if (skb_queue_len(&npinfo->txq) == 0 && !netpoll_owner_active(dev)) {
341                 struct netdev_queue *txq;
342 
343                 txq = netdev_pick_tx(dev, skb, NULL);
344 
345                 /* try until next clock tick */
346                 for (tries = jiffies_to_usecs(1)/USEC_PER_POLL;
347                      tries > 0; --tries) {
348                         if (HARD_TX_TRYLOCK(dev, txq)) {
349                                 if (!netif_xmit_stopped(txq))
350                                         status = netpoll_start_xmit(skb, dev, txq);
351 
352                                 HARD_TX_UNLOCK(dev, txq);
353 
354                                 if (status == NETDEV_TX_OK)
355                                         break;
356 
357                         }
358 
359                         /* tickle device maybe there is some cleanup */
360                         netpoll_poll_dev(np->dev);
361 
362                         udelay(USEC_PER_POLL);
363                 }
364 
365                 WARN_ONCE(!irqs_disabled(),
366                         "netpoll_send_skb_on_dev(): %s enabled interrupts in poll (%pF)\n",
367                         dev->name, dev->netdev_ops->ndo_start_xmit);
368 
369         }
370 
371         if (status != NETDEV_TX_OK) {
372                 skb_queue_tail(&npinfo->txq, skb);
373                 schedule_delayed_work(&npinfo->tx_work,0);
374         }
375 }
376 EXPORT_SYMBOL(netpoll_send_skb_on_dev);
377 
378 void netpoll_send_udp(struct netpoll *np, const char *msg, int len)
379 {
380         int total_len, ip_len, udp_len;
381         struct sk_buff *skb;
382         struct udphdr *udph;
383         struct iphdr *iph;
384         struct ethhdr *eth;
385         static atomic_t ip_ident;
386         struct ipv6hdr *ip6h;
387 
388         WARN_ON_ONCE(!irqs_disabled());
389 
390         udp_len = len + sizeof(*udph);
391         if (np->ipv6)
392                 ip_len = udp_len + sizeof(*ip6h);
393         else
394                 ip_len = udp_len + sizeof(*iph);
395 
396         total_len = ip_len + LL_RESERVED_SPACE(np->dev);
397 
398         skb = find_skb(np, total_len + np->dev->needed_tailroom,
399                        total_len - len);
400         if (!skb)
401                 return;
402 
403         skb_copy_to_linear_data(skb, msg, len);
404         skb_put(skb, len);
405 
406         skb_push(skb, sizeof(*udph));
407         skb_reset_transport_header(skb);
408         udph = udp_hdr(skb);
409         udph->source = htons(np->local_port);
410         udph->dest = htons(np->remote_port);
411         udph->len = htons(udp_len);
412 
413         if (np->ipv6) {
414                 udph->check = 0;
415                 udph->check = csum_ipv6_magic(&np->local_ip.in6,
416                                               &np->remote_ip.in6,
417                                               udp_len, IPPROTO_UDP,
418                                               csum_partial(udph, udp_len, 0));
419                 if (udph->check == 0)
420                         udph->check = CSUM_MANGLED_0;
421 
422                 skb_push(skb, sizeof(*ip6h));
423                 skb_reset_network_header(skb);
424                 ip6h = ipv6_hdr(skb);
425 
426                 /* ip6h->version = 6; ip6h->priority = 0; */
427                 put_unaligned(0x60, (unsigned char *)ip6h);
428                 ip6h->flow_lbl[0] = 0;
429                 ip6h->flow_lbl[1] = 0;
430                 ip6h->flow_lbl[2] = 0;
431 
432                 ip6h->payload_len = htons(sizeof(struct udphdr) + len);
433                 ip6h->nexthdr = IPPROTO_UDP;
434                 ip6h->hop_limit = 32;
435                 ip6h->saddr = np->local_ip.in6;
436                 ip6h->daddr = np->remote_ip.in6;
437 
438                 eth = (struct ethhdr *) skb_push(skb, ETH_HLEN);
439                 skb_reset_mac_header(skb);
440                 skb->protocol = eth->h_proto = htons(ETH_P_IPV6);
441         } else {
442                 udph->check = 0;
443                 udph->check = csum_tcpudp_magic(np->local_ip.ip,
444                                                 np->remote_ip.ip,
445                                                 udp_len, IPPROTO_UDP,
446                                                 csum_partial(udph, udp_len, 0));
447                 if (udph->check == 0)
448                         udph->check = CSUM_MANGLED_0;
449 
450                 skb_push(skb, sizeof(*iph));
451                 skb_reset_network_header(skb);
452                 iph = ip_hdr(skb);
453 
454                 /* iph->version = 4; iph->ihl = 5; */
455                 put_unaligned(0x45, (unsigned char *)iph);
456                 iph->tos      = 0;
457                 put_unaligned(htons(ip_len), &(iph->tot_len));
458                 iph->id       = htons(atomic_inc_return(&ip_ident));
459                 iph->frag_off = 0;
460                 iph->ttl      = 64;
461                 iph->protocol = IPPROTO_UDP;
462                 iph->check    = 0;
463                 put_unaligned(np->local_ip.ip, &(iph->saddr));
464                 put_unaligned(np->remote_ip.ip, &(iph->daddr));
465                 iph->check    = ip_fast_csum((unsigned char *)iph, iph->ihl);
466 
467                 eth = (struct ethhdr *) skb_push(skb, ETH_HLEN);
468                 skb_reset_mac_header(skb);
469                 skb->protocol = eth->h_proto = htons(ETH_P_IP);
470         }
471 
472         ether_addr_copy(eth->h_source, np->dev->dev_addr);
473         ether_addr_copy(eth->h_dest, np->remote_mac);
474 
475         skb->dev = np->dev;
476 
477         netpoll_send_skb(np, skb);
478 }
479 EXPORT_SYMBOL(netpoll_send_udp);
480 
481 void netpoll_print_options(struct netpoll *np)
482 {
483         np_info(np, "local port %d\n", np->local_port);
484         if (np->ipv6)
485                 np_info(np, "local IPv6 address %pI6c\n", &np->local_ip.in6);
486         else
487                 np_info(np, "local IPv4 address %pI4\n", &np->local_ip.ip);
488         np_info(np, "interface '%s'\n", np->dev_name);
489         np_info(np, "remote port %d\n", np->remote_port);
490         if (np->ipv6)
491                 np_info(np, "remote IPv6 address %pI6c\n", &np->remote_ip.in6);
492         else
493                 np_info(np, "remote IPv4 address %pI4\n", &np->remote_ip.ip);
494         np_info(np, "remote ethernet address %pM\n", np->remote_mac);
495 }
496 EXPORT_SYMBOL(netpoll_print_options);
497 
498 static int netpoll_parse_ip_addr(const char *str, union inet_addr *addr)
499 {
500         const char *end;
501 
502         if (!strchr(str, ':') &&
503             in4_pton(str, -1, (void *)addr, -1, &end) > 0) {
504                 if (!*end)
505                         return 0;
506         }
507         if (in6_pton(str, -1, addr->in6.s6_addr, -1, &end) > 0) {
508 #if IS_ENABLED(CONFIG_IPV6)
509                 if (!*end)
510                         return 1;
511 #else
512                 return -1;
513 #endif
514         }
515         return -1;
516 }
517 
518 int netpoll_parse_options(struct netpoll *np, char *opt)
519 {
520         char *cur=opt, *delim;
521         int ipv6;
522         bool ipversion_set = false;
523 
524         if (*cur != '@') {
525                 if ((delim = strchr(cur, '@')) == NULL)
526                         goto parse_failed;
527                 *delim = 0;
528                 if (kstrtou16(cur, 10, &np->local_port))
529                         goto parse_failed;
530                 cur = delim;
531         }
532         cur++;
533 
534         if (*cur != '/') {
535                 ipversion_set = true;
536                 if ((delim = strchr(cur, '/')) == NULL)
537                         goto parse_failed;
538                 *delim = 0;
539                 ipv6 = netpoll_parse_ip_addr(cur, &np->local_ip);
540                 if (ipv6 < 0)
541                         goto parse_failed;
542                 else
543                         np->ipv6 = (bool)ipv6;
544                 cur = delim;
545         }
546         cur++;
547 
548         if (*cur != ',') {
549                 /* parse out dev name */
550                 if ((delim = strchr(cur, ',')) == NULL)
551                         goto parse_failed;
552                 *delim = 0;
553                 strlcpy(np->dev_name, cur, sizeof(np->dev_name));
554                 cur = delim;
555         }
556         cur++;
557 
558         if (*cur != '@') {
559                 /* dst port */
560                 if ((delim = strchr(cur, '@')) == NULL)
561                         goto parse_failed;
562                 *delim = 0;
563                 if (*cur == ' ' || *cur == '\t')
564                         np_info(np, "warning: whitespace is not allowed\n");
565                 if (kstrtou16(cur, 10, &np->remote_port))
566                         goto parse_failed;
567                 cur = delim;
568         }
569         cur++;
570 
571         /* dst ip */
572         if ((delim = strchr(cur, '/')) == NULL)
573                 goto parse_failed;
574         *delim = 0;
575         ipv6 = netpoll_parse_ip_addr(cur, &np->remote_ip);
576         if (ipv6 < 0)
577                 goto parse_failed;
578         else if (ipversion_set && np->ipv6 != (bool)ipv6)
579                 goto parse_failed;
580         else
581                 np->ipv6 = (bool)ipv6;
582         cur = delim + 1;
583 
584         if (*cur != 0) {
585                 /* MAC address */
586                 if (!mac_pton(cur, np->remote_mac))
587                         goto parse_failed;
588         }
589 
590         netpoll_print_options(np);
591 
592         return 0;
593 
594  parse_failed:
595         np_info(np, "couldn't parse config at '%s'!\n", cur);
596         return -1;
597 }
598 EXPORT_SYMBOL(netpoll_parse_options);
599 
600 int __netpoll_setup(struct netpoll *np, struct net_device *ndev)
601 {
602         struct netpoll_info *npinfo;
603         const struct net_device_ops *ops;
604         int err;
605 
606         np->dev = ndev;
607         strlcpy(np->dev_name, ndev->name, IFNAMSIZ);
608         INIT_WORK(&np->cleanup_work, netpoll_async_cleanup);
609 
610         if ((ndev->priv_flags & IFF_DISABLE_NETPOLL) ||
611             !ndev->netdev_ops->ndo_poll_controller) {
612                 np_err(np, "%s doesn't support polling, aborting\n",
613                        np->dev_name);
614                 err = -ENOTSUPP;
615                 goto out;
616         }
617 
618         if (!ndev->npinfo) {
619                 npinfo = kmalloc(sizeof(*npinfo), GFP_KERNEL);
620                 if (!npinfo) {
621                         err = -ENOMEM;
622                         goto out;
623                 }
624 
625                 sema_init(&npinfo->dev_lock, 1);
626                 skb_queue_head_init(&npinfo->txq);
627                 INIT_DELAYED_WORK(&npinfo->tx_work, queue_process);
628 
629                 atomic_set(&npinfo->refcnt, 1);
630 
631                 ops = np->dev->netdev_ops;
632                 if (ops->ndo_netpoll_setup) {
633                         err = ops->ndo_netpoll_setup(ndev, npinfo);
634                         if (err)
635                                 goto free_npinfo;
636                 }
637         } else {
638                 npinfo = rtnl_dereference(ndev->npinfo);
639                 atomic_inc(&npinfo->refcnt);
640         }
641 
642         npinfo->netpoll = np;
643 
644         /* last thing to do is link it to the net device structure */
645         rcu_assign_pointer(ndev->npinfo, npinfo);
646 
647         return 0;
648 
649 free_npinfo:
650         kfree(npinfo);
651 out:
652         return err;
653 }
654 EXPORT_SYMBOL_GPL(__netpoll_setup);
655 
656 int netpoll_setup(struct netpoll *np)
657 {
658         struct net_device *ndev = NULL;
659         struct in_device *in_dev;
660         int err;
661 
662         rtnl_lock();
663         if (np->dev_name) {
664                 struct net *net = current->nsproxy->net_ns;
665                 ndev = __dev_get_by_name(net, np->dev_name);
666         }
667         if (!ndev) {
668                 np_err(np, "%s doesn't exist, aborting\n", np->dev_name);
669                 err = -ENODEV;
670                 goto unlock;
671         }
672         dev_hold(ndev);
673 
674         if (netdev_master_upper_dev_get(ndev)) {
675                 np_err(np, "%s is a slave device, aborting\n", np->dev_name);
676                 err = -EBUSY;
677                 goto put;
678         }
679 
680         if (!netif_running(ndev)) {
681                 unsigned long atmost, atleast;
682 
683                 np_info(np, "device %s not up yet, forcing it\n", np->dev_name);
684 
685                 err = dev_open(ndev);
686 
687                 if (err) {
688                         np_err(np, "failed to open %s\n", ndev->name);
689                         goto put;
690                 }
691 
692                 rtnl_unlock();
693                 atleast = jiffies + HZ/10;
694                 atmost = jiffies + carrier_timeout * HZ;
695                 while (!netif_carrier_ok(ndev)) {
696                         if (time_after(jiffies, atmost)) {
697                                 np_notice(np, "timeout waiting for carrier\n");
698                                 break;
699                         }
700                         msleep(1);
701                 }
702 
703                 /* If carrier appears to come up instantly, we don't
704                  * trust it and pause so that we don't pump all our
705                  * queued console messages into the bitbucket.
706                  */
707 
708                 if (time_before(jiffies, atleast)) {
709                         np_notice(np, "carrier detect appears untrustworthy, waiting 4 seconds\n");
710                         msleep(4000);
711                 }
712                 rtnl_lock();
713         }
714 
715         if (!np->local_ip.ip) {
716                 if (!np->ipv6) {
717                         in_dev = __in_dev_get_rtnl(ndev);
718 
719                         if (!in_dev || !in_dev->ifa_list) {
720                                 np_err(np, "no IP address for %s, aborting\n",
721                                        np->dev_name);
722                                 err = -EDESTADDRREQ;
723                                 goto put;
724                         }
725 
726                         np->local_ip.ip = in_dev->ifa_list->ifa_local;
727                         np_info(np, "local IP %pI4\n", &np->local_ip.ip);
728                 } else {
729 #if IS_ENABLED(CONFIG_IPV6)
730                         struct inet6_dev *idev;
731 
732                         err = -EDESTADDRREQ;
733                         idev = __in6_dev_get(ndev);
734                         if (idev) {
735                                 struct inet6_ifaddr *ifp;
736 
737                                 read_lock_bh(&idev->lock);
738                                 list_for_each_entry(ifp, &idev->addr_list, if_list) {
739                                         if (ipv6_addr_type(&ifp->addr) & IPV6_ADDR_LINKLOCAL)
740                                                 continue;
741                                         np->local_ip.in6 = ifp->addr;
742                                         err = 0;
743                                         break;
744                                 }
745                                 read_unlock_bh(&idev->lock);
746                         }
747                         if (err) {
748                                 np_err(np, "no IPv6 address for %s, aborting\n",
749                                        np->dev_name);
750                                 goto put;
751                         } else
752                                 np_info(np, "local IPv6 %pI6c\n", &np->local_ip.in6);
753 #else
754                         np_err(np, "IPv6 is not supported %s, aborting\n",
755                                np->dev_name);
756                         err = -EINVAL;
757                         goto put;
758 #endif
759                 }
760         }
761 
762         /* fill up the skb queue */
763         refill_skbs();
764 
765         err = __netpoll_setup(np, ndev);
766         if (err)
767                 goto put;
768 
769         rtnl_unlock();
770         return 0;
771 
772 put:
773         dev_put(ndev);
774 unlock:
775         rtnl_unlock();
776         return err;
777 }
778 EXPORT_SYMBOL(netpoll_setup);
779 
780 static int __init netpoll_init(void)
781 {
782         skb_queue_head_init(&skb_pool);
783         return 0;
784 }
785 core_initcall(netpoll_init);
786 
787 static void rcu_cleanup_netpoll_info(struct rcu_head *rcu_head)
788 {
789         struct netpoll_info *npinfo =
790                         container_of(rcu_head, struct netpoll_info, rcu);
791 
792         skb_queue_purge(&npinfo->txq);
793 
794         /* we can't call cancel_delayed_work_sync here, as we are in softirq */
795         cancel_delayed_work(&npinfo->tx_work);
796 
797         /* clean after last, unfinished work */
798         __skb_queue_purge(&npinfo->txq);
799         /* now cancel it again */
800         cancel_delayed_work(&npinfo->tx_work);
801         kfree(npinfo);
802 }
803 
804 void __netpoll_cleanup(struct netpoll *np)
805 {
806         struct netpoll_info *npinfo;
807 
808         /* rtnl_dereference would be preferable here but
809          * rcu_cleanup_netpoll path can put us in here safely without
810          * holding the rtnl, so plain rcu_dereference it is
811          */
812         npinfo = rtnl_dereference(np->dev->npinfo);
813         if (!npinfo)
814                 return;
815 
816         synchronize_srcu(&netpoll_srcu);
817 
818         if (atomic_dec_and_test(&npinfo->refcnt)) {
819                 const struct net_device_ops *ops;
820 
821                 ops = np->dev->netdev_ops;
822                 if (ops->ndo_netpoll_cleanup)
823                         ops->ndo_netpoll_cleanup(np->dev);
824 
825                 RCU_INIT_POINTER(np->dev->npinfo, NULL);
826                 call_rcu_bh(&npinfo->rcu, rcu_cleanup_netpoll_info);
827         } else
828                 RCU_INIT_POINTER(np->dev->npinfo, NULL);
829 }
830 EXPORT_SYMBOL_GPL(__netpoll_cleanup);
831 
832 static void netpoll_async_cleanup(struct work_struct *work)
833 {
834         struct netpoll *np = container_of(work, struct netpoll, cleanup_work);
835 
836         rtnl_lock();
837         __netpoll_cleanup(np);
838         rtnl_unlock();
839         kfree(np);
840 }
841 
842 void __netpoll_free_async(struct netpoll *np)
843 {
844         schedule_work(&np->cleanup_work);
845 }
846 EXPORT_SYMBOL_GPL(__netpoll_free_async);
847 
848 void netpoll_cleanup(struct netpoll *np)
849 {
850         rtnl_lock();
851         if (!np->dev)
852                 goto out;
853         __netpoll_cleanup(np);
854         dev_put(np->dev);
855         np->dev = NULL;
856 out:
857         rtnl_unlock();
858 }
859 EXPORT_SYMBOL(netpoll_cleanup);
860 

~ [ source navigation ] ~ [ diff markup ] ~ [ identifier search ] ~

kernel.org | git.kernel.org | LWN.net | Project Home | Wiki (Japanese) | Wiki (English) | SVN repository | Mail admin

Linux® is a registered trademark of Linus Torvalds in the United States and other countries.
TOMOYO® is a registered trademark of NTT DATA CORPORATION.

osdn.jp