SAFE public projects git trees. - safe/jmp/linux-2.6/blob - net/core/netpoll.c

   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 #include <linux/smp_lock.h>
  13 #include <linux/netdevice.h>
  14 #include <linux/etherdevice.h>
  15 #include <linux/string.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 /*
  29  * We maintain a small pool of fully-sized skbs, to make sure the
  30  * message gets out even in extreme OOM situations.
  31  */
  32
  33 #define MAX_UDP_CHUNK 1460
  34 #define MAX_SKBS 32
  35 #define MAX_QUEUE_DEPTH (MAX_SKBS / 2)
  36 #define MAX_RETRIES 20000
  37
  38 static DEFINE_SPINLOCK(skb_list_lock);
  39 static int nr_skbs;
  40 static struct sk_buff *skbs;
  41
  42 static DEFINE_SPINLOCK(queue_lock);
  43 static int queue_depth;
  44 static struct sk_buff *queue_head, *queue_tail;
  45
  46 static atomic_t trapped;
  47
  48 #define NETPOLL_RX_ENABLED  1
  49 #define NETPOLL_RX_DROP     2
  50
  51 #define MAX_SKB_SIZE \
  52                 (MAX_UDP_CHUNK + sizeof(struct udphdr) + \
  53                                 sizeof(struct iphdr) + sizeof(struct ethhdr))
  54
  55 static void zap_completion_queue(void);
  56
  57 static void queue_process(void *p)
  58 {
  59         unsigned long flags;
  60         struct sk_buff *skb;
  61
  62         while (queue_head) {
  63                 spin_lock_irqsave(&queue_lock, flags);
  64
  65                 skb = queue_head;
  66                 queue_head = skb->next;
  67                 if (skb == queue_tail)
  68                         queue_head = NULL;
  69
  70                 queue_depth--;
  71
  72                 spin_unlock_irqrestore(&queue_lock, flags);
  73
  74                 dev_queue_xmit(skb);
  75         }
  76 }
  77
  78 static DECLARE_WORK(send_queue, queue_process, NULL);
  79
  80 void netpoll_queue(struct sk_buff *skb)
  81 {
  82         unsigned long flags;
  83
  84         if (queue_depth == MAX_QUEUE_DEPTH) {
  85                 __kfree_skb(skb);
  86                 return;
  87         }
  88
  89         spin_lock_irqsave(&queue_lock, flags);
  90         if (!queue_head)
  91                 queue_head = skb;
  92         else
  93                 queue_tail->next = skb;
  94         queue_tail = skb;
  95         queue_depth++;
  96         spin_unlock_irqrestore(&queue_lock, flags);
  97
  98         schedule_work(&send_queue);
  99 }
 100
 101 static int checksum_udp(struct sk_buff *skb, struct udphdr *uh,
 102                              unsigned short ulen, u32 saddr, u32 daddr)
 103 {
 104         if (uh->check == 0)
 105                 return 0;
 106
 107         if (skb->ip_summed == CHECKSUM_HW)
 108                 return csum_tcpudp_magic(
 109                         saddr, daddr, ulen, IPPROTO_UDP, skb->csum);
 110
 111         skb->csum = csum_tcpudp_nofold(saddr, daddr, ulen, IPPROTO_UDP, 0);
 112
 113         return csum_fold(skb_checksum(skb, 0, skb->len, skb->csum));
 114 }
 115
 116 /*
 117  * Check whether delayed processing was scheduled for our NIC. If so,
 118  * we attempt to grab the poll lock and use ->poll() to pump the card.
 119  * If this fails, either we've recursed in ->poll() or it's already
 120  * running on another CPU.
 121  *
 122  * Note: we don't mask interrupts with this lock because we're using
 123  * trylock here and interrupts are already disabled in the softirq
 124  * case. Further, we test the poll_owner to avoid recursion on UP
 125  * systems where the lock doesn't exist.
 126  *
 127  * In cases where there is bi-directional communications, reading only
 128  * one message at a time can lead to packets being dropped by the
 129  * network adapter, forcing superfluous retries and possibly timeouts.
 130  * Thus, we set our budget to greater than 1.
 131  */
 132 static void poll_napi(struct netpoll *np)
 133 {
 134         struct netpoll_info *npinfo = np->dev->npinfo;
 135         int budget = 16;
 136
 137         if (test_bit(__LINK_STATE_RX_SCHED, &np->dev->state) &&
 138             npinfo->poll_owner != smp_processor_id() &&
 139             spin_trylock(&npinfo->poll_lock)) {
 140                 npinfo->rx_flags |= NETPOLL_RX_DROP;
 141                 atomic_inc(&trapped);
 142
 143                 np->dev->poll(np->dev, &budget);
 144
 145                 atomic_dec(&trapped);
 146                 npinfo->rx_flags &= ~NETPOLL_RX_DROP;
 147                 spin_unlock(&npinfo->poll_lock);
 148         }
 149 }
 150
 151 void netpoll_poll(struct netpoll *np)
 152 {
 153         if(!np->dev || !netif_running(np->dev) || !np->dev->poll_controller)
 154                 return;
 155
 156         /* Process pending work on NIC */
 157         np->dev->poll_controller(np->dev);
 158         if (np->dev->poll)
 159                 poll_napi(np);
 160
 161         zap_completion_queue();
 162 }
 163
 164 static void refill_skbs(void)
 165 {
 166         struct sk_buff *skb;
 167         unsigned long flags;
 168
 169         spin_lock_irqsave(&skb_list_lock, flags);
 170         while (nr_skbs < MAX_SKBS) {
 171                 skb = alloc_skb(MAX_SKB_SIZE, GFP_ATOMIC);
 172                 if (!skb)
 173                         break;
 174
 175                 skb->next = skbs;
 176                 skbs = skb;
 177                 nr_skbs++;
 178         }
 179         spin_unlock_irqrestore(&skb_list_lock, flags);
 180 }
 181
 182 static void zap_completion_queue(void)
 183 {
 184         unsigned long flags;
 185         struct softnet_data *sd = &get_cpu_var(softnet_data);
 186
 187         if (sd->completion_queue) {
 188                 struct sk_buff *clist;
 189
 190                 local_irq_save(flags);
 191                 clist = sd->completion_queue;
 192                 sd->completion_queue = NULL;
 193                 local_irq_restore(flags);
 194
 195                 while (clist != NULL) {
 196                         struct sk_buff *skb = clist;
 197                         clist = clist->next;
 198                         if(skb->destructor)
 199                                 dev_kfree_skb_any(skb); /* put this one back */
 200                         else
 201                                 __kfree_skb(skb);
 202                 }
 203         }
 204
 205         put_cpu_var(softnet_data);
 206 }
 207
 208 static struct sk_buff * find_skb(struct netpoll *np, int len, int reserve)
 209 {
 210         int once = 1, count = 0;
 211         unsigned long flags;
 212         struct sk_buff *skb = NULL;
 213
 214         zap_completion_queue();
 215 repeat:
 216         if (nr_skbs < MAX_SKBS)
 217                 refill_skbs();
 218
 219         skb = alloc_skb(len, GFP_ATOMIC);
 220
 221         if (!skb) {
 222                 spin_lock_irqsave(&skb_list_lock, flags);
 223                 skb = skbs;
 224                 if (skb) {
 225                         skbs = skb->next;
 226                         skb->next = NULL;
 227                         nr_skbs--;
 228                 }
 229                 spin_unlock_irqrestore(&skb_list_lock, flags);
 230         }
 231
 232         if(!skb) {
 233                 count++;
 234                 if (once && (count == 1000000)) {
 235                         printk("out of netpoll skbs!\n");
 236                         once = 0;
 237                 }
 238                 netpoll_poll(np);
 239                 goto repeat;
 240         }
 241
 242         atomic_set(&skb->users, 1);
 243         skb_reserve(skb, reserve);
 244         return skb;
 245 }
 246
 247 static void netpoll_send_skb(struct netpoll *np, struct sk_buff *skb)
 248 {
 249         int status;
 250         struct netpoll_info *npinfo;
 251
 252         if (!np || !np->dev || !netif_running(np->dev)) {
 253                 __kfree_skb(skb);
 254                 return;
 255         }
 256
 257         npinfo = np->dev->npinfo;
 258
 259         /* avoid recursion */
 260         if (npinfo->poll_owner == smp_processor_id() ||
 261             np->dev->xmit_lock_owner == smp_processor_id()) {
 262                 if (np->drop)
 263                         np->drop(skb);
 264                 else
 265                         __kfree_skb(skb);
 266                 return;
 267         }
 268
 269         do {
 270                 npinfo->tries--;
 271                 spin_lock(&np->dev->xmit_lock);
 272                 np->dev->xmit_lock_owner = smp_processor_id();
 273
 274                 /*
 275                  * network drivers do not expect to be called if the queue is
 276                  * stopped.
 277                  */
 278                 if (netif_queue_stopped(np->dev)) {
 279                         np->dev->xmit_lock_owner = -1;
 280                         spin_unlock(&np->dev->xmit_lock);
 281                         netpoll_poll(np);
 282                         udelay(50);
 283                         continue;
 284                 }
 285
 286                 status = np->dev->hard_start_xmit(skb, np->dev);
 287                 np->dev->xmit_lock_owner = -1;
 288                 spin_unlock(&np->dev->xmit_lock);
 289
 290                 /* success */
 291                 if(!status) {
 292                         npinfo->tries = MAX_RETRIES; /* reset */
 293                         return;
 294                 }
 295
 296                 /* transmit busy */
 297                 netpoll_poll(np);
 298                 udelay(50);
 299         } while (npinfo->tries > 0);
 300 }
 301
 302 void netpoll_send_udp(struct netpoll *np, const char *msg, int len)
 303 {
 304         int total_len, eth_len, ip_len, udp_len;
 305         struct sk_buff *skb;
 306         struct udphdr *udph;
 307         struct iphdr *iph;
 308         struct ethhdr *eth;
 309
 310         udp_len = len + sizeof(*udph);
 311         ip_len = eth_len = udp_len + sizeof(*iph);
 312         total_len = eth_len + ETH_HLEN + NET_IP_ALIGN;
 313
 314         skb = find_skb(np, total_len, total_len - len);
 315         if (!skb)
 316                 return;
 317
 318         memcpy(skb->data, msg, len);
 319         skb->len += len;
 320
 321         udph = (struct udphdr *) skb_push(skb, sizeof(*udph));
 322         udph->source = htons(np->local_port);
 323         udph->dest = htons(np->remote_port);
 324         udph->len = htons(udp_len);
 325         udph->check = 0;
 326
 327         iph = (struct iphdr *)skb_push(skb, sizeof(*iph));
 328
 329         /* iph->version = 4; iph->ihl = 5; */
 330         put_unaligned(0x45, (unsigned char *)iph);
 331         iph->tos      = 0;
 332         put_unaligned(htons(ip_len), &(iph->tot_len));
 333         iph->id       = 0;
 334         iph->frag_off = 0;
 335         iph->ttl      = 64;
 336         iph->protocol = IPPROTO_UDP;
 337         iph->check    = 0;
 338         put_unaligned(htonl(np->local_ip), &(iph->saddr));
 339         put_unaligned(htonl(np->remote_ip), &(iph->daddr));
 340         iph->check    = ip_fast_csum((unsigned char *)iph, iph->ihl);
 341
 342         eth = (struct ethhdr *) skb_push(skb, ETH_HLEN);
 343
 344         eth->h_proto = htons(ETH_P_IP);
 345         memcpy(eth->h_source, np->local_mac, 6);
 346         memcpy(eth->h_dest, np->remote_mac, 6);
 347
 348         skb->dev = np->dev;
 349
 350         netpoll_send_skb(np, skb);
 351 }
 352
 353 static void arp_reply(struct sk_buff *skb)
 354 {
 355         struct netpoll_info *npinfo = skb->dev->npinfo;
 356         struct arphdr *arp;
 357         unsigned char *arp_ptr;
 358         int size, type = ARPOP_REPLY, ptype = ETH_P_ARP;
 359         u32 sip, tip;
 360         unsigned long flags;
 361         struct sk_buff *send_skb;
 362         struct netpoll *np = NULL;
 363
 364         if (npinfo->rx_np && npinfo->rx_np->dev == skb->dev)
 365                 np = npinfo->rx_np;
 366         if (!np)
 367                 return;
 368
 369         /* No arp on this interface */
 370         if (skb->dev->flags & IFF_NOARP)
 371                 return;
 372
 373         if (!pskb_may_pull(skb, (sizeof(struct arphdr) +
 374                                  (2 * skb->dev->addr_len) +
 375                                  (2 * sizeof(u32)))))
 376                 return;
 377
 378         skb->h.raw = skb->nh.raw = skb->data;
 379         arp = skb->nh.arph;
 380
 381         if ((arp->ar_hrd != htons(ARPHRD_ETHER) &&
 382              arp->ar_hrd != htons(ARPHRD_IEEE802)) ||
 383             arp->ar_pro != htons(ETH_P_IP) ||
 384             arp->ar_op != htons(ARPOP_REQUEST))
 385                 return;
 386
 387         arp_ptr = (unsigned char *)(arp+1) + skb->dev->addr_len;
 388         memcpy(&sip, arp_ptr, 4);
 389         arp_ptr += 4 + skb->dev->addr_len;
 390         memcpy(&tip, arp_ptr, 4);
 391
 392         /* Should we ignore arp? */
 393         if (tip != htonl(np->local_ip) || LOOPBACK(tip) || MULTICAST(tip))
 394                 return;
 395
 396         size = sizeof(struct arphdr) + 2 * (skb->dev->addr_len + 4);
 397         send_skb = find_skb(np, size + LL_RESERVED_SPACE(np->dev),
 398                             LL_RESERVED_SPACE(np->dev));
 399
 400         if (!send_skb)
 401                 return;
 402
 403         send_skb->nh.raw = send_skb->data;
 404         arp = (struct arphdr *) skb_put(send_skb, size);
 405         send_skb->dev = skb->dev;
 406         send_skb->protocol = htons(ETH_P_ARP);
 407
 408         /* Fill the device header for the ARP frame */
 409
 410         if (np->dev->hard_header &&
 411             np->dev->hard_header(send_skb, skb->dev, ptype,
 412                                        np->remote_mac, np->local_mac,
 413                                        send_skb->len) < 0) {
 414                 kfree_skb(send_skb);
 415                 return;
 416         }
 417
 418         /*
 419          * Fill out the arp protocol part.
 420          *
 421          * we only support ethernet device type,
 422          * which (according to RFC 1390) should always equal 1 (Ethernet).
 423          */
 424
 425         arp->ar_hrd = htons(np->dev->type);
 426         arp->ar_pro = htons(ETH_P_IP);
 427         arp->ar_hln = np->dev->addr_len;
 428         arp->ar_pln = 4;
 429         arp->ar_op = htons(type);
 430
 431         arp_ptr=(unsigned char *)(arp + 1);
 432         memcpy(arp_ptr, np->dev->dev_addr, np->dev->addr_len);
 433         arp_ptr += np->dev->addr_len;
 434         memcpy(arp_ptr, &tip, 4);
 435         arp_ptr += 4;
 436         memcpy(arp_ptr, np->remote_mac, np->dev->addr_len);
 437         arp_ptr += np->dev->addr_len;
 438         memcpy(arp_ptr, &sip, 4);
 439
 440         netpoll_send_skb(np, send_skb);
 441 }
 442
 443 int __netpoll_rx(struct sk_buff *skb)
 444 {
 445         int proto, len, ulen;
 446         struct iphdr *iph;
 447         struct udphdr *uh;
 448         struct netpoll *np = skb->dev->npinfo->rx_np;
 449
 450         if (!np)
 451                 goto out;
 452         if (skb->dev->type != ARPHRD_ETHER)
 453                 goto out;
 454
 455         /* check if netpoll clients need ARP */
 456         if (skb->protocol == __constant_htons(ETH_P_ARP) &&
 457             atomic_read(&trapped)) {
 458                 arp_reply(skb);
 459                 return 1;
 460         }
 461
 462         proto = ntohs(eth_hdr(skb)->h_proto);
 463         if (proto != ETH_P_IP)
 464                 goto out;
 465         if (skb->pkt_type == PACKET_OTHERHOST)
 466                 goto out;
 467         if (skb_shared(skb))
 468                 goto out;
 469
 470         iph = (struct iphdr *)skb->data;
 471         if (!pskb_may_pull(skb, sizeof(struct iphdr)))
 472                 goto out;
 473         if (iph->ihl < 5 || iph->version != 4)
 474                 goto out;
 475         if (!pskb_may_pull(skb, iph->ihl*4))
 476                 goto out;
 477         if (ip_fast_csum((u8 *)iph, iph->ihl) != 0)
 478                 goto out;
 479
 480         len = ntohs(iph->tot_len);
 481         if (skb->len < len || len < iph->ihl*4)
 482                 goto out;
 483
 484         if (iph->protocol != IPPROTO_UDP)
 485                 goto out;
 486
 487         len -= iph->ihl*4;
 488         uh = (struct udphdr *)(((char *)iph) + iph->ihl*4);
 489         ulen = ntohs(uh->len);
 490
 491         if (ulen != len)
 492                 goto out;
 493         if (checksum_udp(skb, uh, ulen, iph->saddr, iph->daddr) < 0)
 494                 goto out;
 495         if (np->local_ip && np->local_ip != ntohl(iph->daddr))
 496                 goto out;
 497         if (np->remote_ip && np->remote_ip != ntohl(iph->saddr))
 498                 goto out;
 499         if (np->local_port && np->local_port != ntohs(uh->dest))
 500                 goto out;
 501
 502         np->rx_hook(np, ntohs(uh->source),
 503                     (char *)(uh+1),
 504                     ulen - sizeof(struct udphdr));
 505
 506         kfree_skb(skb);
 507         return 1;
 508
 509 out:
 510         if (atomic_read(&trapped)) {
 511                 kfree_skb(skb);
 512                 return 1;
 513         }
 514
 515         return 0;
 516 }
 517
 518 int netpoll_parse_options(struct netpoll *np, char *opt)
 519 {
 520         char *cur=opt, *delim;
 521
 522         if(*cur != '@') {
 523                 if ((delim = strchr(cur, '@')) == NULL)
 524                         goto parse_failed;
 525                 *delim=0;
 526                 np->local_port=simple_strtol(cur, NULL, 10);
 527                 cur=delim;
 528         }
 529         cur++;
 530         printk(KERN_INFO "%s: local port %d\n", np->name, np->local_port);
 531
 532         if(*cur != '/') {
 533                 if ((delim = strchr(cur, '/')) == NULL)
 534                         goto parse_failed;
 535                 *delim=0;
 536                 np->local_ip=ntohl(in_aton(cur));
 537                 cur=delim;
 538
 539                 printk(KERN_INFO "%s: local IP %d.%d.%d.%d\n",
 540                        np->name, HIPQUAD(np->local_ip));
 541         }
 542         cur++;
 543
 544         if ( *cur != ',') {
 545                 /* parse out dev name */
 546                 if ((delim = strchr(cur, ',')) == NULL)
 547                         goto parse_failed;
 548                 *delim=0;
 549                 strlcpy(np->dev_name, cur, sizeof(np->dev_name));
 550                 cur=delim;
 551         }
 552         cur++;
 553
 554         printk(KERN_INFO "%s: interface %s\n", np->name, np->dev_name);
 555
 556         if ( *cur != '@' ) {
 557                 /* dst port */
 558                 if ((delim = strchr(cur, '@')) == NULL)
 559                         goto parse_failed;
 560                 *delim=0;
 561                 np->remote_port=simple_strtol(cur, NULL, 10);
 562                 cur=delim;
 563         }
 564         cur++;
 565         printk(KERN_INFO "%s: remote port %d\n", np->name, np->remote_port);
 566
 567         /* dst ip */
 568         if ((delim = strchr(cur, '/')) == NULL)
 569                 goto parse_failed;
 570         *delim=0;
 571         np->remote_ip=ntohl(in_aton(cur));
 572         cur=delim+1;
 573
 574         printk(KERN_INFO "%s: remote IP %d.%d.%d.%d\n",
 575                        np->name, HIPQUAD(np->remote_ip));
 576
 577         if( *cur != 0 )
 578         {
 579                 /* MAC address */
 580                 if ((delim = strchr(cur, ':')) == NULL)
 581                         goto parse_failed;
 582                 *delim=0;
 583                 np->remote_mac[0]=simple_strtol(cur, NULL, 16);
 584                 cur=delim+1;
 585                 if ((delim = strchr(cur, ':')) == NULL)
 586                         goto parse_failed;
 587                 *delim=0;
 588                 np->remote_mac[1]=simple_strtol(cur, NULL, 16);
 589                 cur=delim+1;
 590                 if ((delim = strchr(cur, ':')) == NULL)
 591                         goto parse_failed;
 592                 *delim=0;
 593                 np->remote_mac[2]=simple_strtol(cur, NULL, 16);
 594                 cur=delim+1;
 595                 if ((delim = strchr(cur, ':')) == NULL)
 596                         goto parse_failed;
 597                 *delim=0;
 598                 np->remote_mac[3]=simple_strtol(cur, NULL, 16);
 599                 cur=delim+1;
 600                 if ((delim = strchr(cur, ':')) == NULL)
 601                         goto parse_failed;
 602                 *delim=0;
 603                 np->remote_mac[4]=simple_strtol(cur, NULL, 16);
 604                 cur=delim+1;
 605                 np->remote_mac[5]=simple_strtol(cur, NULL, 16);
 606         }
 607
 608         printk(KERN_INFO "%s: remote ethernet address "
 609                "%02x:%02x:%02x:%02x:%02x:%02x\n",
 610                np->name,
 611                np->remote_mac[0],
 612                np->remote_mac[1],
 613                np->remote_mac[2],
 614                np->remote_mac[3],
 615                np->remote_mac[4],
 616                np->remote_mac[5]);
 617
 618         return 0;
 619
 620  parse_failed:
 621         printk(KERN_INFO "%s: couldn't parse config at %s!\n",
 622                np->name, cur);
 623         return -1;
 624 }
 625
 626 int netpoll_setup(struct netpoll *np)
 627 {
 628         struct net_device *ndev = NULL;
 629         struct in_device *in_dev;
 630         struct netpoll_info *npinfo;
 631         unsigned long flags;
 632
 633         if (np->dev_name)
 634                 ndev = dev_get_by_name(np->dev_name);
 635         if (!ndev) {
 636                 printk(KERN_ERR "%s: %s doesn't exist, aborting.\n",
 637                        np->name, np->dev_name);
 638                 return -1;
 639         }
 640
 641         np->dev = ndev;
 642         if (!ndev->npinfo) {
 643                 npinfo = kmalloc(sizeof(*npinfo), GFP_KERNEL);
 644                 if (!npinfo)
 645                         goto release;
 646
 647                 npinfo->rx_flags = 0;
 648                 npinfo->rx_np = NULL;
 649                 npinfo->poll_lock = SPIN_LOCK_UNLOCKED;
 650                 npinfo->poll_owner = -1;
 651                 npinfo->tries = MAX_RETRIES;
 652                 npinfo->rx_lock = SPIN_LOCK_UNLOCKED;
 653         } else
 654                 npinfo = ndev->npinfo;
 655
 656         if (!ndev->poll_controller) {
 657                 printk(KERN_ERR "%s: %s doesn't support polling, aborting.\n",
 658                        np->name, np->dev_name);
 659                 goto release;
 660         }
 661
 662         if (!netif_running(ndev)) {
 663                 unsigned long atmost, atleast;
 664
 665                 printk(KERN_INFO "%s: device %s not up yet, forcing it\n",
 666                        np->name, np->dev_name);
 667
 668                 rtnl_shlock();
 669                 if (dev_change_flags(ndev, ndev->flags | IFF_UP) < 0) {
 670                         printk(KERN_ERR "%s: failed to open %s\n",
 671                                np->name, np->dev_name);
 672                         rtnl_shunlock();
 673                         goto release;
 674                 }
 675                 rtnl_shunlock();
 676
 677                 atleast = jiffies + HZ/10;
 678                 atmost = jiffies + 4*HZ;
 679                 while (!netif_carrier_ok(ndev)) {
 680                         if (time_after(jiffies, atmost)) {
 681                                 printk(KERN_NOTICE
 682                                        "%s: timeout waiting for carrier\n",
 683                                        np->name);
 684                                 break;
 685                         }
 686                         cond_resched();
 687                 }
 688
 689                 /* If carrier appears to come up instantly, we don't
 690                  * trust it and pause so that we don't pump all our
 691                  * queued console messages into the bitbucket.
 692                  */
 693
 694                 if (time_before(jiffies, atleast)) {
 695                         printk(KERN_NOTICE "%s: carrier detect appears"
 696                                " untrustworthy, waiting 4 seconds\n",
 697                                np->name);
 698                         msleep(4000);
 699                 }
 700         }
 701
 702         if (!memcmp(np->local_mac, "\0\0\0\0\0\0", 6) && ndev->dev_addr)
 703                 memcpy(np->local_mac, ndev->dev_addr, 6);
 704
 705         if (!np->local_ip) {
 706                 rcu_read_lock();
 707                 in_dev = __in_dev_get(ndev);
 708
 709                 if (!in_dev || !in_dev->ifa_list) {
 710                         rcu_read_unlock();
 711                         printk(KERN_ERR "%s: no IP address for %s, aborting\n",
 712                                np->name, np->dev_name);
 713                         goto release;
 714                 }
 715
 716                 np->local_ip = ntohl(in_dev->ifa_list->ifa_local);
 717                 rcu_read_unlock();
 718                 printk(KERN_INFO "%s: local IP %d.%d.%d.%d\n",
 719                        np->name, HIPQUAD(np->local_ip));
 720         }
 721
 722         if (np->rx_hook) {
 723                 spin_lock_irqsave(&npinfo->rx_lock, flags);
 724                 npinfo->rx_flags |= NETPOLL_RX_ENABLED;
 725                 npinfo->rx_np = np;
 726                 spin_unlock_irqrestore(&npinfo->rx_lock, flags);
 727         }
 728
 729         /* fill up the skb queue */
 730         refill_skbs();
 731
 732         /* last thing to do is link it to the net device structure */
 733         ndev->npinfo = npinfo;
 734
 735         return 0;
 736
 737  release:
 738         if (!ndev->npinfo)
 739                 kfree(npinfo);
 740         np->dev = NULL;
 741         dev_put(ndev);
 742         return -1;
 743 }
 744
 745 void netpoll_cleanup(struct netpoll *np)
 746 {
 747         struct netpoll_info *npinfo;
 748         unsigned long flags;
 749
 750         if (np->dev) {
 751                 npinfo = np->dev->npinfo;
 752                 if (npinfo && npinfo->rx_np == np) {
 753                         spin_lock_irqsave(&npinfo->rx_lock, flags);
 754                         npinfo->rx_np = NULL;
 755                         npinfo->rx_flags &= ~NETPOLL_RX_ENABLED;
 756                         spin_unlock_irqrestore(&npinfo->rx_lock, flags);
 757                 }
 758                 dev_put(np->dev);
 759         }
 760
 761         np->dev = NULL;
 762 }
 763
 764 int netpoll_trap(void)
 765 {
 766         return atomic_read(&trapped);
 767 }
 768
 769 void netpoll_set_trap(int trap)
 770 {
 771         if (trap)
 772                 atomic_inc(&trapped);
 773         else
 774                 atomic_dec(&trapped);
 775 }
 776
 777 EXPORT_SYMBOL(netpoll_set_trap);
 778 EXPORT_SYMBOL(netpoll_trap);
 779 EXPORT_SYMBOL(netpoll_parse_options);
 780 EXPORT_SYMBOL(netpoll_setup);
 781 EXPORT_SYMBOL(netpoll_cleanup);
 782 EXPORT_SYMBOL(netpoll_send_udp);
 783 EXPORT_SYMBOL(netpoll_poll);
 784 EXPORT_SYMBOL(netpoll_queue);