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

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

Version: ~ [ linux-5.13-rc1 ] ~ [ linux-5.12.2 ] ~ [ linux-5.11.19 ] ~ [ linux-5.10.35 ] ~ [ linux-5.9.16 ] ~ [ linux-5.8.18 ] ~ [ linux-5.7.19 ] ~ [ linux-5.6.19 ] ~ [ linux-5.5.19 ] ~ [ linux-5.4.117 ] ~ [ linux-5.3.18 ] ~ [ linux-5.2.21 ] ~ [ linux-5.1.21 ] ~ [ linux-5.0.21 ] ~ [ linux-4.20.17 ] ~ [ linux-4.19.190 ] ~ [ linux-4.18.20 ] ~ [ linux-4.17.19 ] ~ [ linux-4.16.18 ] ~ [ linux-4.15.18 ] ~ [ linux-4.14.232 ] ~ [ linux-4.13.16 ] ~ [ linux-4.12.14 ] ~ [ linux-4.11.12 ] ~ [ linux-4.10.17 ] ~ [ linux-4.9.268 ] ~ [ linux-4.8.17 ] ~ [ linux-4.7.10 ] ~ [ linux-4.6.7 ] ~ [ linux-4.5.7 ] ~ [ linux-4.4.268 ] ~ [ 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                 unsigned int q_index;
109 
110                 if (!netif_device_present(dev) || !netif_running(dev)) {
111                         kfree_skb(skb);
112                         continue;
113                 }
114 
115                 local_irq_save(flags);
116                 /* check if skb->queue_mapping is still valid */
117                 q_index = skb_get_queue_mapping(skb);
118                 if (unlikely(q_index >= dev->real_num_tx_queues)) {
119                         q_index = q_index % dev->real_num_tx_queues;
120                         skb_set_queue_mapping(skb, q_index);
121                 }
122                 txq = netdev_get_tx_queue(dev, q_index);
123                 HARD_TX_LOCK(dev, txq, smp_processor_id());
124                 if (netif_xmit_frozen_or_stopped(txq) ||
125                     netpoll_start_xmit(skb, dev, txq) != NETDEV_TX_OK) {
126                         skb_queue_head(&npinfo->txq, skb);
127                         HARD_TX_UNLOCK(dev, txq);
128                         local_irq_restore(flags);
129 
130                         schedule_delayed_work(&npinfo->tx_work, HZ/10);
131                         return;
132                 }
133                 HARD_TX_UNLOCK(dev, txq);
134                 local_irq_restore(flags);
135         }
136 }
137 
138 /*
139  * Check whether delayed processing was scheduled for our NIC. If so,
140  * we attempt to grab the poll lock and use ->poll() to pump the card.
141  * If this fails, either we've recursed in ->poll() or it's already
142  * running on another CPU.
143  *
144  * Note: we don't mask interrupts with this lock because we're using
145  * trylock here and interrupts are already disabled in the softirq
146  * case. Further, we test the poll_owner to avoid recursion on UP
147  * systems where the lock doesn't exist.
148  */
149 static void poll_one_napi(struct napi_struct *napi)
150 {
151         int work = 0;
152 
153         /* net_rx_action's ->poll() invocations and our's are
154          * synchronized by this test which is only made while
155          * holding the napi->poll_lock.
156          */
157         if (!test_bit(NAPI_STATE_SCHED, &napi->state))
158                 return;
159 
160         /* If we set this bit but see that it has already been set,
161          * that indicates that napi has been disabled and we need
162          * to abort this operation
163          */
164         if (test_and_set_bit(NAPI_STATE_NPSVC, &napi->state))
165                 return;
166 
167         /* We explicilty pass the polling call a budget of 0 to
168          * indicate that we are clearing the Tx path only.
169          */
170         work = napi->poll(napi, 0);
171         WARN_ONCE(work, "%pF exceeded budget in poll\n", napi->poll);
172         trace_napi_poll(napi, work, 0);
173 
174         clear_bit(NAPI_STATE_NPSVC, &napi->state);
175 }
176 
177 static void poll_napi(struct net_device *dev)
178 {
179         struct napi_struct *napi;
180         int cpu = smp_processor_id();
181 
182         list_for_each_entry(napi, &dev->napi_list, dev_list) {
183                 if (cmpxchg(&napi->poll_owner, -1, cpu) == -1) {
184                         poll_one_napi(napi);
185                         smp_store_release(&napi->poll_owner, -1);
186                 }
187         }
188 }
189 
190 static void netpoll_poll_dev(struct net_device *dev)
191 {
192         const struct net_device_ops *ops;
193         struct netpoll_info *ni = rcu_dereference_bh(dev->npinfo);
194 
195         /* Don't do any rx activity if the dev_lock mutex is held
196          * the dev_open/close paths use this to block netpoll activity
197          * while changing device state
198          */
199         if (down_trylock(&ni->dev_lock))
200                 return;
201 
202         if (!netif_running(dev)) {
203                 up(&ni->dev_lock);
204                 return;
205         }
206 
207         ops = dev->netdev_ops;
208         if (!ops->ndo_poll_controller) {
209                 up(&ni->dev_lock);
210                 return;
211         }
212 
213         /* Process pending work on NIC */
214         ops->ndo_poll_controller(dev);
215 
216         poll_napi(dev);
217 
218         up(&ni->dev_lock);
219 
220         zap_completion_queue();
221 }
222 
223 void netpoll_poll_disable(struct net_device *dev)
224 {
225         struct netpoll_info *ni;
226         int idx;
227         might_sleep();
228         idx = srcu_read_lock(&netpoll_srcu);
229         ni = srcu_dereference(dev->npinfo, &netpoll_srcu);
230         if (ni)
231                 down(&ni->dev_lock);
232         srcu_read_unlock(&netpoll_srcu, idx);
233 }
234 EXPORT_SYMBOL(netpoll_poll_disable);
235 
236 void netpoll_poll_enable(struct net_device *dev)
237 {
238         struct netpoll_info *ni;
239         rcu_read_lock();
240         ni = rcu_dereference(dev->npinfo);
241         if (ni)
242                 up(&ni->dev_lock);
243         rcu_read_unlock();
244 }
245 EXPORT_SYMBOL(netpoll_poll_enable);
246 
247 static void refill_skbs(void)
248 {
249         struct sk_buff *skb;
250         unsigned long flags;
251 
252         spin_lock_irqsave(&skb_pool.lock, flags);
253         while (skb_pool.qlen < MAX_SKBS) {
254                 skb = alloc_skb(MAX_SKB_SIZE, GFP_ATOMIC);
255                 if (!skb)
256                         break;
257 
258                 __skb_queue_tail(&skb_pool, skb);
259         }
260         spin_unlock_irqrestore(&skb_pool.lock, flags);
261 }
262 
263 static void zap_completion_queue(void)
264 {
265         unsigned long flags;
266         struct softnet_data *sd = &get_cpu_var(softnet_data);
267 
268         if (sd->completion_queue) {
269                 struct sk_buff *clist;
270 
271                 local_irq_save(flags);
272                 clist = sd->completion_queue;
273                 sd->completion_queue = NULL;
274                 local_irq_restore(flags);
275 
276                 while (clist != NULL) {
277                         struct sk_buff *skb = clist;
278                         clist = clist->next;
279                         if (!skb_irq_freeable(skb)) {
280                                 refcount_set(&skb->users, 1);
281                                 dev_kfree_skb_any(skb); /* put this one back */
282                         } else {
283                                 __kfree_skb(skb);
284                         }
285                 }
286         }
287 
288         put_cpu_var(softnet_data);
289 }
290 
291 static struct sk_buff *find_skb(struct netpoll *np, int len, int reserve)
292 {
293         int count = 0;
294         struct sk_buff *skb;
295 
296         zap_completion_queue();
297         refill_skbs();
298 repeat:
299 
300         skb = alloc_skb(len, GFP_ATOMIC);
301         if (!skb)
302                 skb = skb_dequeue(&skb_pool);
303 
304         if (!skb) {
305                 if (++count < 10) {
306                         netpoll_poll_dev(np->dev);
307                         goto repeat;
308                 }
309                 return NULL;
310         }
311 
312         refcount_set(&skb->users, 1);
313         skb_reserve(skb, reserve);
314         return skb;
315 }
316 
317 static int netpoll_owner_active(struct net_device *dev)
318 {
319         struct napi_struct *napi;
320 
321         list_for_each_entry(napi, &dev->napi_list, dev_list) {
322                 if (napi->poll_owner == smp_processor_id())
323                         return 1;
324         }
325         return 0;
326 }
327 
328 /* call with IRQ disabled */
329 void netpoll_send_skb_on_dev(struct netpoll *np, struct sk_buff *skb,
330                              struct net_device *dev)
331 {
332         int status = NETDEV_TX_BUSY;
333         unsigned long tries;
334         /* It is up to the caller to keep npinfo alive. */
335         struct netpoll_info *npinfo;
336 
337         lockdep_assert_irqs_disabled();
338 
339         npinfo = rcu_dereference_bh(np->dev->npinfo);
340         if (!npinfo || !netif_running(dev) || !netif_device_present(dev)) {
341                 dev_kfree_skb_irq(skb);
342                 return;
343         }
344 
345         /* don't get messages out of order, and no recursion */
346         if (skb_queue_len(&npinfo->txq) == 0 && !netpoll_owner_active(dev)) {
347                 struct netdev_queue *txq;
348 
349                 txq = netdev_pick_tx(dev, skb, NULL);
350 
351                 /* try until next clock tick */
352                 for (tries = jiffies_to_usecs(1)/USEC_PER_POLL;
353                      tries > 0; --tries) {
354                         if (HARD_TX_TRYLOCK(dev, txq)) {
355                                 if (!netif_xmit_stopped(txq))
356                                         status = netpoll_start_xmit(skb, dev, txq);
357 
358                                 HARD_TX_UNLOCK(dev, txq);
359 
360                                 if (status == NETDEV_TX_OK)
361                                         break;
362 
363                         }
364 
365                         /* tickle device maybe there is some cleanup */
366                         netpoll_poll_dev(np->dev);
367 
368                         udelay(USEC_PER_POLL);
369                 }
370 
371                 WARN_ONCE(!irqs_disabled(),
372                         "netpoll_send_skb_on_dev(): %s enabled interrupts in poll (%pF)\n",
373                         dev->name, dev->netdev_ops->ndo_start_xmit);
374 
375         }
376 
377         if (status != NETDEV_TX_OK) {
378                 skb_queue_tail(&npinfo->txq, skb);
379                 schedule_delayed_work(&npinfo->tx_work,0);
380         }
381 }
382 EXPORT_SYMBOL(netpoll_send_skb_on_dev);
383 
384 void netpoll_send_udp(struct netpoll *np, const char *msg, int len)
385 {
386         int total_len, ip_len, udp_len;
387         struct sk_buff *skb;
388         struct udphdr *udph;
389         struct iphdr *iph;
390         struct ethhdr *eth;
391         static atomic_t ip_ident;
392         struct ipv6hdr *ip6h;
393 
394         WARN_ON_ONCE(!irqs_disabled());
395 
396         udp_len = len + sizeof(*udph);
397         if (np->ipv6)
398                 ip_len = udp_len + sizeof(*ip6h);
399         else
400                 ip_len = udp_len + sizeof(*iph);
401 
402         total_len = ip_len + LL_RESERVED_SPACE(np->dev);
403 
404         skb = find_skb(np, total_len + np->dev->needed_tailroom,
405                        total_len - len);
406         if (!skb)
407                 return;
408 
409         skb_copy_to_linear_data(skb, msg, len);
410         skb_put(skb, len);
411 
412         skb_push(skb, sizeof(*udph));
413         skb_reset_transport_header(skb);
414         udph = udp_hdr(skb);
415         udph->source = htons(np->local_port);
416         udph->dest = htons(np->remote_port);
417         udph->len = htons(udp_len);
418 
419         if (np->ipv6) {
420                 udph->check = 0;
421                 udph->check = csum_ipv6_magic(&np->local_ip.in6,
422                                               &np->remote_ip.in6,
423                                               udp_len, IPPROTO_UDP,
424                                               csum_partial(udph, udp_len, 0));
425                 if (udph->check == 0)
426                         udph->check = CSUM_MANGLED_0;
427 
428                 skb_push(skb, sizeof(*ip6h));
429                 skb_reset_network_header(skb);
430                 ip6h = ipv6_hdr(skb);
431 
432                 /* ip6h->version = 6; ip6h->priority = 0; */
433                 put_unaligned(0x60, (unsigned char *)ip6h);
434                 ip6h->flow_lbl[0] = 0;
435                 ip6h->flow_lbl[1] = 0;
436                 ip6h->flow_lbl[2] = 0;
437 
438                 ip6h->payload_len = htons(sizeof(struct udphdr) + len);
439                 ip6h->nexthdr = IPPROTO_UDP;
440                 ip6h->hop_limit = 32;
441                 ip6h->saddr = np->local_ip.in6;
442                 ip6h->daddr = np->remote_ip.in6;
443 
444                 eth = skb_push(skb, ETH_HLEN);
445                 skb_reset_mac_header(skb);
446                 skb->protocol = eth->h_proto = htons(ETH_P_IPV6);
447         } else {
448                 udph->check = 0;
449                 udph->check = csum_tcpudp_magic(np->local_ip.ip,
450                                                 np->remote_ip.ip,
451                                                 udp_len, IPPROTO_UDP,
452                                                 csum_partial(udph, udp_len, 0));
453                 if (udph->check == 0)
454                         udph->check = CSUM_MANGLED_0;
455 
456                 skb_push(skb, sizeof(*iph));
457                 skb_reset_network_header(skb);
458                 iph = ip_hdr(skb);
459 
460                 /* iph->version = 4; iph->ihl = 5; */
461                 put_unaligned(0x45, (unsigned char *)iph);
462                 iph->tos      = 0;
463                 put_unaligned(htons(ip_len), &(iph->tot_len));
464                 iph->id       = htons(atomic_inc_return(&ip_ident));
465                 iph->frag_off = 0;
466                 iph->ttl      = 64;
467                 iph->protocol = IPPROTO_UDP;
468                 iph->check    = 0;
469                 put_unaligned(np->local_ip.ip, &(iph->saddr));
470                 put_unaligned(np->remote_ip.ip, &(iph->daddr));
471                 iph->check    = ip_fast_csum((unsigned char *)iph, iph->ihl);
472 
473                 eth = skb_push(skb, ETH_HLEN);
474                 skb_reset_mac_header(skb);
475                 skb->protocol = eth->h_proto = htons(ETH_P_IP);
476         }
477 
478         ether_addr_copy(eth->h_source, np->dev->dev_addr);
479         ether_addr_copy(eth->h_dest, np->remote_mac);
480 
481         skb->dev = np->dev;
482 
483         netpoll_send_skb(np, skb);
484 }
485 EXPORT_SYMBOL(netpoll_send_udp);
486 
487 void netpoll_print_options(struct netpoll *np)
488 {
489         np_info(np, "local port %d\n", np->local_port);
490         if (np->ipv6)
491                 np_info(np, "local IPv6 address %pI6c\n", &np->local_ip.in6);
492         else
493                 np_info(np, "local IPv4 address %pI4\n", &np->local_ip.ip);
494         np_info(np, "interface '%s'\n", np->dev_name);
495         np_info(np, "remote port %d\n", np->remote_port);
496         if (np->ipv6)
497                 np_info(np, "remote IPv6 address %pI6c\n", &np->remote_ip.in6);
498         else
499                 np_info(np, "remote IPv4 address %pI4\n", &np->remote_ip.ip);
500         np_info(np, "remote ethernet address %pM\n", np->remote_mac);
501 }
502 EXPORT_SYMBOL(netpoll_print_options);
503 
504 static int netpoll_parse_ip_addr(const char *str, union inet_addr *addr)
505 {
506         const char *end;
507 
508         if (!strchr(str, ':') &&
509             in4_pton(str, -1, (void *)addr, -1, &end) > 0) {
510                 if (!*end)
511                         return 0;
512         }
513         if (in6_pton(str, -1, addr->in6.s6_addr, -1, &end) > 0) {
514 #if IS_ENABLED(CONFIG_IPV6)
515                 if (!*end)
516                         return 1;
517 #else
518                 return -1;
519 #endif
520         }
521         return -1;
522 }
523 
524 int netpoll_parse_options(struct netpoll *np, char *opt)
525 {
526         char *cur=opt, *delim;
527         int ipv6;
528         bool ipversion_set = false;
529 
530         if (*cur != '@') {
531                 if ((delim = strchr(cur, '@')) == NULL)
532                         goto parse_failed;
533                 *delim = 0;
534                 if (kstrtou16(cur, 10, &np->local_port))
535                         goto parse_failed;
536                 cur = delim;
537         }
538         cur++;
539 
540         if (*cur != '/') {
541                 ipversion_set = true;
542                 if ((delim = strchr(cur, '/')) == NULL)
543                         goto parse_failed;
544                 *delim = 0;
545                 ipv6 = netpoll_parse_ip_addr(cur, &np->local_ip);
546                 if (ipv6 < 0)
547                         goto parse_failed;
548                 else
549                         np->ipv6 = (bool)ipv6;
550                 cur = delim;
551         }
552         cur++;
553 
554         if (*cur != ',') {
555                 /* parse out dev name */
556                 if ((delim = strchr(cur, ',')) == NULL)
557                         goto parse_failed;
558                 *delim = 0;
559                 strlcpy(np->dev_name, cur, sizeof(np->dev_name));
560                 cur = delim;
561         }
562         cur++;
563 
564         if (*cur != '@') {
565                 /* dst port */
566                 if ((delim = strchr(cur, '@')) == NULL)
567                         goto parse_failed;
568                 *delim = 0;
569                 if (*cur == ' ' || *cur == '\t')
570                         np_info(np, "warning: whitespace is not allowed\n");
571                 if (kstrtou16(cur, 10, &np->remote_port))
572                         goto parse_failed;
573                 cur = delim;
574         }
575         cur++;
576 
577         /* dst ip */
578         if ((delim = strchr(cur, '/')) == NULL)
579                 goto parse_failed;
580         *delim = 0;
581         ipv6 = netpoll_parse_ip_addr(cur, &np->remote_ip);
582         if (ipv6 < 0)
583                 goto parse_failed;
584         else if (ipversion_set && np->ipv6 != (bool)ipv6)
585                 goto parse_failed;
586         else
587                 np->ipv6 = (bool)ipv6;
588         cur = delim + 1;
589 
590         if (*cur != 0) {
591                 /* MAC address */
592                 if (!mac_pton(cur, np->remote_mac))
593                         goto parse_failed;
594         }
595 
596         netpoll_print_options(np);
597 
598         return 0;
599 
600  parse_failed:
601         np_info(np, "couldn't parse config at '%s'!\n", cur);
602         return -1;
603 }
604 EXPORT_SYMBOL(netpoll_parse_options);
605 
606 int __netpoll_setup(struct netpoll *np, struct net_device *ndev)
607 {
608         struct netpoll_info *npinfo;
609         const struct net_device_ops *ops;
610         int err;
611 
612         np->dev = ndev;
613         strlcpy(np->dev_name, ndev->name, IFNAMSIZ);
614         INIT_WORK(&np->cleanup_work, netpoll_async_cleanup);
615 
616         if ((ndev->priv_flags & IFF_DISABLE_NETPOLL) ||
617             !ndev->netdev_ops->ndo_poll_controller) {
618                 np_err(np, "%s doesn't support polling, aborting\n",
619                        np->dev_name);
620                 err = -ENOTSUPP;
621                 goto out;
622         }
623 
624         if (!ndev->npinfo) {
625                 npinfo = kmalloc(sizeof(*npinfo), GFP_KERNEL);
626                 if (!npinfo) {
627                         err = -ENOMEM;
628                         goto out;
629                 }
630 
631                 sema_init(&npinfo->dev_lock, 1);
632                 skb_queue_head_init(&npinfo->txq);
633                 INIT_DELAYED_WORK(&npinfo->tx_work, queue_process);
634 
635                 refcount_set(&npinfo->refcnt, 1);
636 
637                 ops = np->dev->netdev_ops;
638                 if (ops->ndo_netpoll_setup) {
639                         err = ops->ndo_netpoll_setup(ndev, npinfo);
640                         if (err)
641                                 goto free_npinfo;
642                 }
643         } else {
644                 npinfo = rtnl_dereference(ndev->npinfo);
645                 refcount_inc(&npinfo->refcnt);
646         }
647 
648         npinfo->netpoll = np;
649 
650         /* last thing to do is link it to the net device structure */
651         rcu_assign_pointer(ndev->npinfo, npinfo);
652 
653         return 0;
654 
655 free_npinfo:
656         kfree(npinfo);
657 out:
658         return err;
659 }
660 EXPORT_SYMBOL_GPL(__netpoll_setup);
661 
662 int netpoll_setup(struct netpoll *np)
663 {
664         struct net_device *ndev = NULL;
665         struct in_device *in_dev;
666         int err;
667 
668         rtnl_lock();
669         if (np->dev_name[0]) {
670                 struct net *net = current->nsproxy->net_ns;
671                 ndev = __dev_get_by_name(net, np->dev_name);
672         }
673         if (!ndev) {
674                 np_err(np, "%s doesn't exist, aborting\n", np->dev_name);
675                 err = -ENODEV;
676                 goto unlock;
677         }
678         dev_hold(ndev);
679 
680         if (netdev_master_upper_dev_get(ndev)) {
681                 np_err(np, "%s is a slave device, aborting\n", np->dev_name);
682                 err = -EBUSY;
683                 goto put;
684         }
685 
686         if (!netif_running(ndev)) {
687                 unsigned long atmost, atleast;
688 
689                 np_info(np, "device %s not up yet, forcing it\n", np->dev_name);
690 
691                 err = dev_open(ndev);
692 
693                 if (err) {
694                         np_err(np, "failed to open %s\n", ndev->name);
695                         goto put;
696                 }
697 
698                 rtnl_unlock();
699                 atleast = jiffies + HZ/10;
700                 atmost = jiffies + carrier_timeout * HZ;
701                 while (!netif_carrier_ok(ndev)) {
702                         if (time_after(jiffies, atmost)) {
703                                 np_notice(np, "timeout waiting for carrier\n");
704                                 break;
705                         }
706                         msleep(1);
707                 }
708 
709                 /* If carrier appears to come up instantly, we don't
710                  * trust it and pause so that we don't pump all our
711                  * queued console messages into the bitbucket.
712                  */
713 
714                 if (time_before(jiffies, atleast)) {
715                         np_notice(np, "carrier detect appears untrustworthy, waiting 4 seconds\n");
716                         msleep(4000);
717                 }
718                 rtnl_lock();
719         }
720 
721         if (!np->local_ip.ip) {
722                 if (!np->ipv6) {
723                         in_dev = __in_dev_get_rtnl(ndev);
724 
725                         if (!in_dev || !in_dev->ifa_list) {
726                                 np_err(np, "no IP address for %s, aborting\n",
727                                        np->dev_name);
728                                 err = -EDESTADDRREQ;
729                                 goto put;
730                         }
731 
732                         np->local_ip.ip = in_dev->ifa_list->ifa_local;
733                         np_info(np, "local IP %pI4\n", &np->local_ip.ip);
734                 } else {
735 #if IS_ENABLED(CONFIG_IPV6)
736                         struct inet6_dev *idev;
737 
738                         err = -EDESTADDRREQ;
739                         idev = __in6_dev_get(ndev);
740                         if (idev) {
741                                 struct inet6_ifaddr *ifp;
742 
743                                 read_lock_bh(&idev->lock);
744                                 list_for_each_entry(ifp, &idev->addr_list, if_list) {
745                                         if (ipv6_addr_type(&ifp->addr) & IPV6_ADDR_LINKLOCAL)
746                                                 continue;
747                                         np->local_ip.in6 = ifp->addr;
748                                         err = 0;
749                                         break;
750                                 }
751                                 read_unlock_bh(&idev->lock);
752                         }
753                         if (err) {
754                                 np_err(np, "no IPv6 address for %s, aborting\n",
755                                        np->dev_name);
756                                 goto put;
757                         } else
758                                 np_info(np, "local IPv6 %pI6c\n", &np->local_ip.in6);
759 #else
760                         np_err(np, "IPv6 is not supported %s, aborting\n",
761                                np->dev_name);
762                         err = -EINVAL;
763                         goto put;
764 #endif
765                 }
766         }
767 
768         /* fill up the skb queue */
769         refill_skbs();
770 
771         err = __netpoll_setup(np, ndev);
772         if (err)
773                 goto put;
774 
775         rtnl_unlock();
776         return 0;
777 
778 put:
779         dev_put(ndev);
780 unlock:
781         rtnl_unlock();
782         return err;
783 }
784 EXPORT_SYMBOL(netpoll_setup);
785 
786 static int __init netpoll_init(void)
787 {
788         skb_queue_head_init(&skb_pool);
789         return 0;
790 }
791 core_initcall(netpoll_init);
792 
793 static void rcu_cleanup_netpoll_info(struct rcu_head *rcu_head)
794 {
795         struct netpoll_info *npinfo =
796                         container_of(rcu_head, struct netpoll_info, rcu);
797 
798         skb_queue_purge(&npinfo->txq);
799 
800         /* we can't call cancel_delayed_work_sync here, as we are in softirq */
801         cancel_delayed_work(&npinfo->tx_work);
802 
803         /* clean after last, unfinished work */
804         __skb_queue_purge(&npinfo->txq);
805         /* now cancel it again */
806         cancel_delayed_work(&npinfo->tx_work);
807         kfree(npinfo);
808 }
809 
810 void __netpoll_cleanup(struct netpoll *np)
811 {
812         struct netpoll_info *npinfo;
813 
814         /* rtnl_dereference would be preferable here but
815          * rcu_cleanup_netpoll path can put us in here safely without
816          * holding the rtnl, so plain rcu_dereference it is
817          */
818         npinfo = rtnl_dereference(np->dev->npinfo);
819         if (!npinfo)
820                 return;
821 
822         synchronize_srcu(&netpoll_srcu);
823 
824         if (refcount_dec_and_test(&npinfo->refcnt)) {
825                 const struct net_device_ops *ops;
826 
827                 ops = np->dev->netdev_ops;
828                 if (ops->ndo_netpoll_cleanup)
829                         ops->ndo_netpoll_cleanup(np->dev);
830 
831                 RCU_INIT_POINTER(np->dev->npinfo, NULL);
832                 call_rcu_bh(&npinfo->rcu, rcu_cleanup_netpoll_info);
833         } else
834                 RCU_INIT_POINTER(np->dev->npinfo, NULL);
835 }
836 EXPORT_SYMBOL_GPL(__netpoll_cleanup);
837 
838 static void netpoll_async_cleanup(struct work_struct *work)
839 {
840         struct netpoll *np = container_of(work, struct netpoll, cleanup_work);
841 
842         rtnl_lock();
843         __netpoll_cleanup(np);
844         rtnl_unlock();
845         kfree(np);
846 }
847 
848 void __netpoll_free_async(struct netpoll *np)
849 {
850         schedule_work(&np->cleanup_work);
851 }
852 EXPORT_SYMBOL_GPL(__netpoll_free_async);
853 
854 void netpoll_cleanup(struct netpoll *np)
855 {
856         rtnl_lock();
857         if (!np->dev)
858                 goto out;
859         __netpoll_cleanup(np);
860         dev_put(np->dev);
861         np->dev = NULL;
862 out:
863         rtnl_unlock();
864 }
865 EXPORT_SYMBOL(netpoll_cleanup);
866 

~ [ 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