FreeRTOS/Common/ethernet/lwIP_132/src/core/netif.c

   1 /**
   2  * @file
   3  * lwIP network interface abstraction
   4  *
   5  */
   6
   7 /*
   8  * Copyright (c) 2001-2004 Swedish Institute of Computer Science.
   9  * All rights reserved.
  10  *
  11  * Redistribution and use in source and binary forms, with or without modification,
  12  * are permitted provided that the following conditions are met:
  13  *
  14  * 1. Redistributions of source code must retain the above copyright notice,
  15  *    this list of conditions and the following disclaimer.
  16  * 2. Redistributions in binary form must reproduce the above copyright notice,
  17  *    this list of conditions and the following disclaimer in the documentation
  18  *    and/or other materials provided with the distribution.
  19  * 3. The name of the author may not be used to endorse or promote products
  20  *    derived from this software without specific prior written permission.
  21  *
  22  * THIS SOFTWARE IS PROVIDED BY THE AUTHOR ``AS IS'' AND ANY EXPRESS OR IMPLIED
  23  * WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE IMPLIED WARRANTIES OF
  24  * MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE ARE DISCLAIMED. IN NO EVENT
  25  * SHALL THE AUTHOR BE LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL,
  26  * EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT
  27  * OF SUBSTITUTE GOODS OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS
  28  * INTERRUPTION) HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN
  29  * CONTRACT, STRICT LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING
  30  * IN ANY WAY OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY
  31  * OF SUCH DAMAGE.
  32  *
  33  * This file is part of the lwIP TCP/IP stack.
  34  *
  35  * Author: Adam Dunkels <adam@sics.se>
  36  *
  37  */
  38
  39 #include "lwip/opt.h"
  40
  41 #include "lwip/def.h"
  42 #include "lwip/ip_addr.h"
  43 #include "lwip/netif.h"
  44 #include "lwip/tcp.h"
  45 #include "lwip/snmp.h"
  46 #include "lwip/igmp.h"
  47 #include "netif/etharp.h"
  48 #if ENABLE_LOOPBACK
  49 #include "lwip/sys.h"
  50 #if LWIP_NETIF_LOOPBACK_MULTITHREADING
  51 #include "lwip/tcpip.h"
  52 #endif /* LWIP_NETIF_LOOPBACK_MULTITHREADING */
  53 #endif /* ENABLE_LOOPBACK */
  54
  55 #if LWIP_AUTOIP
  56 #include "lwip/autoip.h"
  57 #endif /* LWIP_AUTOIP */
  58 #if LWIP_DHCP
  59 #include "lwip/dhcp.h"
  60 #endif /* LWIP_DHCP */
  61
  62 #if LWIP_NETIF_STATUS_CALLBACK
  63 #define NETIF_STATUS_CALLBACK(n) { if (n->status_callback) (n->status_callback)(n); }
  64 #else
  65 #define NETIF_STATUS_CALLBACK(n) { /* NOP */ }
  66 #endif /* LWIP_NETIF_STATUS_CALLBACK */
  67
  68 #if LWIP_NETIF_LINK_CALLBACK
  69 #define NETIF_LINK_CALLBACK(n) { if (n->link_callback) (n->link_callback)(n); }
  70 #else
  71 #define NETIF_LINK_CALLBACK(n) { /* NOP */ }
  72 #endif /* LWIP_NETIF_LINK_CALLBACK */
  73
  74 struct netif *netif_list;
  75 struct netif *netif_default;
  76
  77 /**
  78  * Add a network interface to the list of lwIP netifs.
  79  *
  80  * @param netif a pre-allocated netif structure
  81  * @param ipaddr IP address for the new netif
  82  * @param netmask network mask for the new netif
  83  * @param gw default gateway IP address for the new netif
  84  * @param state opaque data passed to the new netif
  85  * @param init callback function that initializes the interface
  86  * @param input callback function that is called to pass
  87  * ingress packets up in the protocol layer stack.
  88  *
  89  * @return netif, or NULL if failed.
  90  */
  91 struct netif *
  92 netif_add(struct netif *netif, struct ip_addr *ipaddr, struct ip_addr *netmask,
  93   struct ip_addr *gw,
  94   void *state,
  95   err_t (* init)(struct netif *netif),
  96   err_t (* input)(struct pbuf *p, struct netif *netif))
  97 {
  98   static u8_t netifnum = 0;
  99
 100   /* reset new interface configuration state */
 101   netif->ip_addr.addr = 0;
 102   netif->netmask.addr = 0;
 103   netif->gw.addr = 0;
 104   netif->flags = 0;
 105 #if LWIP_DHCP
 106   /* netif not under DHCP control by default */
 107   netif->dhcp = NULL;
 108 #endif /* LWIP_DHCP */
 109 #if LWIP_AUTOIP
 110   /* netif not under AutoIP control by default */
 111   netif->autoip = NULL;
 112 #endif /* LWIP_AUTOIP */
 113 #if LWIP_NETIF_STATUS_CALLBACK
 114   netif->status_callback = NULL;
 115 #endif /* LWIP_NETIF_STATUS_CALLBACK */
 116 #if LWIP_NETIF_LINK_CALLBACK
 117   netif->link_callback = NULL;
 118 #endif /* LWIP_NETIF_LINK_CALLBACK */
 119 #if LWIP_IGMP
 120   netif->igmp_mac_filter = NULL;
 121 #endif /* LWIP_IGMP */
 122 #if ENABLE_LOOPBACK
 123   netif->loop_first = NULL;
 124   netif->loop_last = NULL;
 125 #endif /* ENABLE_LOOPBACK */
 126
 127   /* remember netif specific state information data */
 128   netif->state = state;
 129   netif->num = netifnum++;
 130   netif->input = input;
 131 #if LWIP_NETIF_HWADDRHINT
 132   netif->addr_hint = NULL;
 133 #endif /* LWIP_NETIF_HWADDRHINT*/
 134 #if ENABLE_LOOPBACK && LWIP_LOOPBACK_MAX_PBUFS
 135   netif->loop_cnt_current = 0;
 136 #endif /* ENABLE_LOOPBACK && LWIP_LOOPBACK_MAX_PBUFS */
 137
 138   netif_set_addr(netif, ipaddr, netmask, gw);
 139
 140   /* call user specified initialization function for netif */
 141   if (init(netif) != ERR_OK) {
 142     return NULL;
 143   }
 144
 145   /* add this netif to the list */
 146   netif->next = netif_list;
 147   netif_list = netif;
 148   snmp_inc_iflist();
 149
 150 #if LWIP_IGMP
 151   /* start IGMP processing */
 152   if (netif->flags & NETIF_FLAG_IGMP) {
 153     igmp_start( netif);
 154   }
 155 #endif /* LWIP_IGMP */
 156
 157   LWIP_DEBUGF(NETIF_DEBUG, ("netif: added interface %c%c IP addr ",
 158     netif->name[0], netif->name[1]));
 159   ip_addr_debug_print(NETIF_DEBUG, ipaddr);
 160   LWIP_DEBUGF(NETIF_DEBUG, (" netmask "));
 161   ip_addr_debug_print(NETIF_DEBUG, netmask);
 162   LWIP_DEBUGF(NETIF_DEBUG, (" gw "));
 163   ip_addr_debug_print(NETIF_DEBUG, gw);
 164   LWIP_DEBUGF(NETIF_DEBUG, ("\n"));
 165   return netif;
 166 }
 167
 168 /**
 169  * Change IP address configuration for a network interface (including netmask
 170  * and default gateway).
 171  *
 172  * @param netif the network interface to change
 173  * @param ipaddr the new IP address
 174  * @param netmask the new netmask
 175  * @param gw the new default gateway
 176  */
 177 void
 178 netif_set_addr(struct netif *netif, struct ip_addr *ipaddr, struct ip_addr *netmask,
 179     struct ip_addr *gw)
 180 {
 181   netif_set_ipaddr(netif, ipaddr);
 182   netif_set_netmask(netif, netmask);
 183   netif_set_gw(netif, gw);
 184 }
 185
 186 /**
 187  * Remove a network interface from the list of lwIP netifs.
 188  *
 189  * @param netif the network interface to remove
 190  */
 191 void netif_remove(struct netif * netif)
 192 {
 193   if ( netif == NULL ) return;
 194
 195 #if LWIP_IGMP
 196   /* stop IGMP processing */
 197   if (netif->flags & NETIF_FLAG_IGMP) {
 198     igmp_stop( netif);
 199   }
 200 #endif /* LWIP_IGMP */
 201
 202   snmp_delete_ipaddridx_tree(netif);
 203
 204   /*  is it the first netif? */
 205   if (netif_list == netif) {
 206     netif_list = netif->next;
 207     snmp_dec_iflist();
 208   }
 209   else {
 210     /*  look for netif further down the list */
 211     struct netif * tmpNetif;
 212     for (tmpNetif = netif_list; tmpNetif != NULL; tmpNetif = tmpNetif->next) {
 213       if (tmpNetif->next == netif) {
 214         tmpNetif->next = netif->next;
 215         snmp_dec_iflist();
 216         break;
 217       }
 218     }
 219     if (tmpNetif == NULL)
 220       return; /*  we didn't find any netif today */
 221   }
 222   /* this netif is default? */
 223   if (netif_default == netif)
 224     /* reset default netif */
 225     netif_set_default(NULL);
 226   LWIP_DEBUGF( NETIF_DEBUG, ("netif_remove: removed netif\n") );
 227 }
 228
 229 /**
 230  * Find a network interface by searching for its name
 231  *
 232  * @param name the name of the netif (like netif->name) plus concatenated number
 233  * in ascii representation (e.g. 'en0')
 234  */
 235 struct netif *
 236 netif_find(char *name)
 237 {
 238   struct netif *netif;
 239   u8_t num;
 240
 241   if (name == NULL) {
 242     return NULL;
 243   }
 244
 245   num = name[2] - '0';
 246
 247   for(netif = netif_list; netif != NULL; netif = netif->next) {
 248     if (num == netif->num &&
 249        name[0] == netif->name[0] &&
 250        name[1] == netif->name[1]) {
 251       LWIP_DEBUGF(NETIF_DEBUG, ("netif_find: found %c%c\n", name[0], name[1]));
 252       return netif;
 253     }
 254   }
 255   LWIP_DEBUGF(NETIF_DEBUG, ("netif_find: didn't find %c%c\n", name[0], name[1]));
 256   return NULL;
 257 }
 258
 259 /**
 260  * Change the IP address of a network interface
 261  *
 262  * @param netif the network interface to change
 263  * @param ipaddr the new IP address
 264  *
 265  * @note call netif_set_addr() if you also want to change netmask and
 266  * default gateway
 267  */
 268 void
 269 netif_set_ipaddr(struct netif *netif, struct ip_addr *ipaddr)
 270 {
 271   /* TODO: Handling of obsolete pcbs */
 272   /* See:  http://mail.gnu.org/archive/html/lwip-users/2003-03/msg00118.html */
 273 #if LWIP_TCP
 274   struct tcp_pcb *pcb;
 275   struct tcp_pcb_listen *lpcb;
 276
 277   /* address is actually being changed? */
 278   if ((ip_addr_cmp(ipaddr, &(netif->ip_addr))) == 0)
 279   {
 280     /* extern struct tcp_pcb *tcp_active_pcbs; defined by tcp.h */
 281     LWIP_DEBUGF(NETIF_DEBUG | LWIP_DBG_STATE, ("netif_set_ipaddr: netif address being changed\n"));
 282     pcb = tcp_active_pcbs;
 283     while (pcb != NULL) {
 284       /* PCB bound to current local interface address? */
 285       if (ip_addr_cmp(&(pcb->local_ip), &(netif->ip_addr))) {
 286         /* this connection must be aborted */
 287         struct tcp_pcb *next = pcb->next;
 288         LWIP_DEBUGF(NETIF_DEBUG | LWIP_DBG_STATE, ("netif_set_ipaddr: aborting TCP pcb %p\n", (void *)pcb));
 289         tcp_abort(pcb);
 290         pcb = next;
 291       } else {
 292         pcb = pcb->next;
 293       }
 294     }
 295     for (lpcb = tcp_listen_pcbs.listen_pcbs; lpcb != NULL; lpcb = lpcb->next) {
 296       /* PCB bound to current local interface address? */
 297       if ((!(ip_addr_isany(&(lpcb->local_ip)))) &&
 298           (ip_addr_cmp(&(lpcb->local_ip), &(netif->ip_addr)))) {
 299         /* The PCB is listening to the old ipaddr and
 300          * is set to listen to the new one instead */
 301         ip_addr_set(&(lpcb->local_ip), ipaddr);
 302       }
 303     }
 304   }
 305 #endif
 306   snmp_delete_ipaddridx_tree(netif);
 307   snmp_delete_iprteidx_tree(0,netif);
 308   /* set new IP address to netif */
 309   ip_addr_set(&(netif->ip_addr), ipaddr);
 310   snmp_insert_ipaddridx_tree(netif);
 311   snmp_insert_iprteidx_tree(0,netif);
 312
 313   LWIP_DEBUGF(NETIF_DEBUG | LWIP_DBG_TRACE | LWIP_DBG_STATE, ("netif: IP address of interface %c%c set to %"U16_F".%"U16_F".%"U16_F".%"U16_F"\n",
 314     netif->name[0], netif->name[1],
 315     ip4_addr1(&netif->ip_addr),
 316     ip4_addr2(&netif->ip_addr),
 317     ip4_addr3(&netif->ip_addr),
 318     ip4_addr4(&netif->ip_addr)));
 319 }
 320
 321 /**
 322  * Change the default gateway for a network interface
 323  *
 324  * @param netif the network interface to change
 325  * @param gw the new default gateway
 326  *
 327  * @note call netif_set_addr() if you also want to change ip address and netmask
 328  */
 329 void
 330 netif_set_gw(struct netif *netif, struct ip_addr *gw)
 331 {
 332   ip_addr_set(&(netif->gw), gw);
 333   LWIP_DEBUGF(NETIF_DEBUG | LWIP_DBG_TRACE | LWIP_DBG_STATE, ("netif: GW address of interface %c%c set to %"U16_F".%"U16_F".%"U16_F".%"U16_F"\n",
 334     netif->name[0], netif->name[1],
 335     ip4_addr1(&netif->gw),
 336     ip4_addr2(&netif->gw),
 337     ip4_addr3(&netif->gw),
 338     ip4_addr4(&netif->gw)));
 339 }
 340
 341 /**
 342  * Change the netmask of a network interface
 343  *
 344  * @param netif the network interface to change
 345  * @param netmask the new netmask
 346  *
 347  * @note call netif_set_addr() if you also want to change ip address and
 348  * default gateway
 349  */
 350 void
 351 netif_set_netmask(struct netif *netif, struct ip_addr *netmask)
 352 {
 353   snmp_delete_iprteidx_tree(0, netif);
 354   /* set new netmask to netif */
 355   ip_addr_set(&(netif->netmask), netmask);
 356   snmp_insert_iprteidx_tree(0, netif);
 357   LWIP_DEBUGF(NETIF_DEBUG | LWIP_DBG_TRACE | LWIP_DBG_STATE, ("netif: netmask of interface %c%c set to %"U16_F".%"U16_F".%"U16_F".%"U16_F"\n",
 358     netif->name[0], netif->name[1],
 359     ip4_addr1(&netif->netmask),
 360     ip4_addr2(&netif->netmask),
 361     ip4_addr3(&netif->netmask),
 362     ip4_addr4(&netif->netmask)));
 363 }
 364
 365 /**
 366  * Set a network interface as the default network interface
 367  * (used to output all packets for which no specific route is found)
 368  *
 369  * @param netif the default network interface
 370  */
 371 void
 372 netif_set_default(struct netif *netif)
 373 {
 374   if (netif == NULL)
 375   {
 376     /* remove default route */
 377     snmp_delete_iprteidx_tree(1, netif);
 378   }
 379   else
 380   {
 381     /* install default route */
 382     snmp_insert_iprteidx_tree(1, netif);
 383   }
 384   netif_default = netif;
 385   LWIP_DEBUGF(NETIF_DEBUG, ("netif: setting default interface %c%c\n",
 386            netif ? netif->name[0] : '\'', netif ? netif->name[1] : '\''));
 387 }
 388
 389 /**
 390  * Bring an interface up, available for processing
 391  * traffic.
 392  *
 393  * @note: Enabling DHCP on a down interface will make it come
 394  * up once configured.
 395  *
 396  * @see dhcp_start()
 397  */
 398 void netif_set_up(struct netif *netif)
 399 {
 400   if ( !(netif->flags & NETIF_FLAG_UP )) {
 401     netif->flags |= NETIF_FLAG_UP;
 402
 403 #if LWIP_SNMP
 404     snmp_get_sysuptime(&netif->ts);
 405 #endif /* LWIP_SNMP */
 406
 407     NETIF_LINK_CALLBACK(netif);
 408     NETIF_STATUS_CALLBACK(netif);
 409
 410 #if LWIP_ARP
 411     /* For Ethernet network interfaces, we would like to send a "gratuitous ARP" */
 412     if (netif->flags & NETIF_FLAG_ETHARP) {
 413       etharp_gratuitous(netif);
 414     }
 415 #endif /* LWIP_ARP */
 416
 417 #if LWIP_IGMP
 418     /* resend IGMP memberships */
 419     if (netif->flags & NETIF_FLAG_IGMP) {
 420       igmp_report_groups( netif);
 421     }
 422 #endif /* LWIP_IGMP */
 423   }
 424 }
 425
 426 /**
 427  * Bring an interface down, disabling any traffic processing.
 428  *
 429  * @note: Enabling DHCP on a down interface will make it come
 430  * up once configured.
 431  *
 432  * @see dhcp_start()
 433  */
 434 void netif_set_down(struct netif *netif)
 435 {
 436   if ( netif->flags & NETIF_FLAG_UP )
 437     {
 438       netif->flags &= ~NETIF_FLAG_UP;
 439 #if LWIP_SNMP
 440       snmp_get_sysuptime(&netif->ts);
 441 #endif
 442
 443       NETIF_LINK_CALLBACK(netif);
 444       NETIF_STATUS_CALLBACK(netif);
 445     }
 446 }
 447
 448 /**
 449  * Ask if an interface is up
 450  */
 451 u8_t netif_is_up(struct netif *netif)
 452 {
 453   return (netif->flags & NETIF_FLAG_UP)?1:0;
 454 }
 455
 456 #if LWIP_NETIF_STATUS_CALLBACK
 457 /**
 458  * Set callback to be called when interface is brought up/down
 459  */
 460 void netif_set_status_callback(struct netif *netif, void (* status_callback)(struct netif *netif ))
 461 {
 462     if ( netif )
 463         netif->status_callback = status_callback;
 464 }
 465 #endif /* LWIP_NETIF_STATUS_CALLBACK */
 466
 467 #if LWIP_NETIF_LINK_CALLBACK
 468 /**
 469  * Called by a driver when its link goes up
 470  */
 471 void netif_set_link_up(struct netif *netif )
 472 {
 473   netif->flags |= NETIF_FLAG_LINK_UP;
 474
 475 #if LWIP_DHCP
 476   if (netif->dhcp) {
 477     dhcp_network_changed(netif);
 478   }
 479 #endif /* LWIP_DHCP */
 480
 481 #if LWIP_AUTOIP
 482   if (netif->autoip) {
 483     autoip_network_changed(netif);
 484   }
 485 #endif /* LWIP_AUTOIP */
 486
 487   if (netif->flags & NETIF_FLAG_UP) {
 488 #if LWIP_ARP
 489   /* For Ethernet network interfaces, we would like to send a "gratuitous ARP" */
 490   if (netif->flags & NETIF_FLAG_ETHARP) {
 491     etharp_gratuitous(netif);
 492   }
 493 #endif /* LWIP_ARP */
 494
 495 #if LWIP_IGMP
 496     /* resend IGMP memberships */
 497     if (netif->flags & NETIF_FLAG_IGMP) {
 498       igmp_report_groups( netif);
 499     }
 500 #endif /* LWIP_IGMP */
 501   }
 502   NETIF_LINK_CALLBACK(netif);
 503 }
 504
 505 /**
 506  * Called by a driver when its link goes down
 507  */
 508 void netif_set_link_down(struct netif *netif )
 509 {
 510   netif->flags &= ~NETIF_FLAG_LINK_UP;
 511   NETIF_LINK_CALLBACK(netif);
 512 }
 513
 514 /**
 515  * Ask if a link is up
 516  */
 517 u8_t netif_is_link_up(struct netif *netif)
 518 {
 519   return (netif->flags & NETIF_FLAG_LINK_UP) ? 1 : 0;
 520 }
 521
 522 /**
 523  * Set callback to be called when link is brought up/down
 524  */
 525 void netif_set_link_callback(struct netif *netif, void (* link_callback)(struct netif *netif ))
 526 {
 527   if (netif) {
 528     netif->link_callback = link_callback;
 529   }
 530 }
 531 #endif /* LWIP_NETIF_LINK_CALLBACK */
 532
 533 #if ENABLE_LOOPBACK
 534 /**
 535  * Send an IP packet to be received on the same netif (loopif-like).
 536  * The pbuf is simply copied and handed back to netif->input.
 537  * In multithreaded mode, this is done directly since netif->input must put
 538  * the packet on a queue.
 539  * In callback mode, the packet is put on an internal queue and is fed to
 540  * netif->input by netif_poll().
 541  *
 542  * @param netif the lwip network interface structure
 543  * @param p the (IP) packet to 'send'
 544  * @param ipaddr the ip address to send the packet to (not used)
 545  * @return ERR_OK if the packet has been sent
 546  *         ERR_MEM if the pbuf used to copy the packet couldn't be allocated
 547  */
 548 err_t
 549 netif_loop_output(struct netif *netif, struct pbuf *p,
 550        struct ip_addr *ipaddr)
 551 {
 552   struct pbuf *r;
 553   err_t err;
 554   struct pbuf *last;
 555 #if LWIP_LOOPBACK_MAX_PBUFS
 556   u8_t clen = 0;
 557 #endif /* LWIP_LOOPBACK_MAX_PBUFS */
 558   SYS_ARCH_DECL_PROTECT(lev);
 559   LWIP_UNUSED_ARG(ipaddr);
 560
 561   /* Allocate a new pbuf */
 562   r = pbuf_alloc(PBUF_LINK, p->tot_len, PBUF_RAM);
 563   if (r == NULL) {
 564     return ERR_MEM;
 565   }
 566 #if LWIP_LOOPBACK_MAX_PBUFS
 567   clen = pbuf_clen(r);
 568   /* check for overflow or too many pbuf on queue */
 569   if(((netif->loop_cnt_current + clen) < netif->loop_cnt_current) ||
 570     ((netif->loop_cnt_current + clen) > LWIP_LOOPBACK_MAX_PBUFS)) {
 571       pbuf_free(r);
 572       r = NULL;
 573       return ERR_MEM;
 574   }
 575   netif->loop_cnt_current += clen;
 576 #endif /* LWIP_LOOPBACK_MAX_PBUFS */
 577
 578   /* Copy the whole pbuf queue p into the single pbuf r */
 579   if ((err = pbuf_copy(r, p)) != ERR_OK) {
 580     pbuf_free(r);
 581     r = NULL;
 582     return err;
 583   }
 584
 585   /* Put the packet on a linked list which gets emptied through calling
 586      netif_poll(). */
 587
 588   /* let last point to the last pbuf in chain r */
 589   for (last = r; last->next != NULL; last = last->next);
 590
 591   SYS_ARCH_PROTECT(lev);
 592   if(netif->loop_first != NULL) {
 593     LWIP_ASSERT("if first != NULL, last must also be != NULL", netif->loop_last != NULL);
 594     netif->loop_last->next = r;
 595     netif->loop_last = last;
 596   } else {
 597     netif->loop_first = r;
 598     netif->loop_last = last;
 599   }
 600   SYS_ARCH_UNPROTECT(lev);
 601
 602 #if LWIP_NETIF_LOOPBACK_MULTITHREADING
 603   /* For multithreading environment, schedule a call to netif_poll */
 604   tcpip_callback((void (*)(void *))(netif_poll), netif);
 605 #endif /* LWIP_NETIF_LOOPBACK_MULTITHREADING */
 606
 607   return ERR_OK;
 608 }
 609
 610 /**
 611  * Call netif_poll() in the main loop of your application. This is to prevent
 612  * reentering non-reentrant functions like tcp_input(). Packets passed to
 613  * netif_loop_output() are put on a list that is passed to netif->input() by
 614  * netif_poll().
 615  */
 616 void
 617 netif_poll(struct netif *netif)
 618 {
 619   struct pbuf *in;
 620   SYS_ARCH_DECL_PROTECT(lev);
 621
 622   do {
 623     /* Get a packet from the list. With SYS_LIGHTWEIGHT_PROT=1, this is protected */
 624     SYS_ARCH_PROTECT(lev);
 625     in = netif->loop_first;
 626     if(in != NULL) {
 627       struct pbuf *in_end = in;
 628 #if LWIP_LOOPBACK_MAX_PBUFS
 629       u8_t clen = pbuf_clen(in);
 630       /* adjust the number of pbufs on queue */
 631       LWIP_ASSERT("netif->loop_cnt_current underflow",
 632         ((netif->loop_cnt_current - clen) < netif->loop_cnt_current));
 633       netif->loop_cnt_current -= clen;
 634 #endif /* LWIP_LOOPBACK_MAX_PBUFS */
 635       while(in_end->len != in_end->tot_len) {
 636         LWIP_ASSERT("bogus pbuf: len != tot_len but next == NULL!", in_end->next != NULL);
 637         in_end = in_end->next;
 638       }
 639       /* 'in_end' now points to the last pbuf from 'in' */
 640       if(in_end == netif->loop_last) {
 641         /* this was the last pbuf in the list */
 642         netif->loop_first = netif->loop_last = NULL;
 643       } else {
 644         /* pop the pbuf off the list */
 645         netif->loop_first = in_end->next;
 646         LWIP_ASSERT("should not be null since first != last!", netif->loop_first != NULL);
 647       }
 648       /* De-queue the pbuf from its successors on the 'loop_' list. */
 649       in_end->next = NULL;
 650     }
 651     SYS_ARCH_UNPROTECT(lev);
 652
 653     if(in != NULL) {
 654       /* loopback packets are always IP packets! */
 655       if(ip_input(in, netif) != ERR_OK) {
 656         pbuf_free(in);
 657       }
 658       /* Don't reference the packet any more! */
 659       in = NULL;
 660     }
 661   /* go on while there is a packet on the list */
 662   } while(netif->loop_first != NULL);
 663 }
 664
 665 #if !LWIP_NETIF_LOOPBACK_MULTITHREADING
 666 /**
 667  * Calls netif_poll() for every netif on the netif_list.
 668  */
 669 void
 670 netif_poll_all(void)
 671 {
 672   struct netif *netif = netif_list;
 673   /* loop through netifs */
 674   while (netif != NULL) {
 675     netif_poll(netif);
 676     /* proceed to next network interface */
 677     netif = netif->next;
 678   }
 679 }
 680 #endif /* !LWIP_NETIF_LOOPBACK_MULTITHREADING */
 681 #endif /* ENABLE_LOOPBACK */