netif.c

00001 /**
00002  * @file
00003  * lwIP network interface abstraction
00004  *
00005  */
00006 
00007 /*
00008  * Copyright (c) 2001-2004 Swedish Institute of Computer Science.
00009  * All rights reserved.
00010  *
00011  * Redistribution and use in source and binary forms, with or without modification,
00012  * are permitted provided that the following conditions are met:
00013  *
00014  * 1. Redistributions of source code must retain the above copyright notice,
00015  *    this list of conditions and the following disclaimer.
00016  * 2. Redistributions in binary form must reproduce the above copyright notice,
00017  *    this list of conditions and the following disclaimer in the documentation
00018  *    and/or other materials provided with the distribution.
00019  * 3. The name of the author may not be used to endorse or promote products
00020  *    derived from this software without specific prior written permission.
00021  *
00022  * THIS SOFTWARE IS PROVIDED BY THE AUTHOR ``AS IS'' AND ANY EXPRESS OR IMPLIED
00023  * WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE IMPLIED WARRANTIES OF
00024  * MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE ARE DISCLAIMED. IN NO EVENT
00025  * SHALL THE AUTHOR BE LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL,
00026  * EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT
00027  * OF SUBSTITUTE GOODS OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS
00028  * INTERRUPTION) HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN
00029  * CONTRACT, STRICT LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING
00030  * IN ANY WAY OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY
00031  * OF SUCH DAMAGE.
00032  *
00033  * This file is part of the lwIP TCP/IP stack.
00034  *
00035  * Author: Adam Dunkels <adam@sics.se>
00036  *
00037  */
00038 
00039 #include "lwip/opt.h"
00040 
00041 #include "lwip/def.h"
00042 #include "lwip/ip_addr.h"
00043 #include "lwip/netif.h"
00044 #include "lwip/tcp.h"
00045 #include "lwip/snmp.h"
00046 #include "lwip/igmp.h"
00047 #include "netif/etharp.h"
00048 #if ENABLE_LOOPBACK
00049 #include "lwip/sys.h"
00050 #if LWIP_NETIF_LOOPBACK_MULTITHREADING
00051 #include "lwip/tcpip.h"
00052 #endif /* LWIP_NETIF_LOOPBACK_MULTITHREADING */
00053 #endif /* ENABLE_LOOPBACK */
00054 
00055 #if LWIP_AUTOIP
00056 #include "lwip/autoip.h"
00057 #endif /* LWIP_AUTOIP */
00058 #if LWIP_DHCP
00059 #include "lwip/dhcp.h "
00060 #endif /* LWIP_DHCP */
00061 
00062 #if LWIP_NETIF_STATUS_CALLBACK
00063 #define NETIF_STATUS_CALLBACK(n) { if (n->status_callback) (n->status_callback)(n); }
00064 #else
00065 #define NETIF_STATUS_CALLBACK(n) { /* NOP */ }
00066 #endif /* LWIP_NETIF_STATUS_CALLBACK */ 
00067 
00068 #if LWIP_NETIF_LINK_CALLBACK
00069 #define NETIF_LINK_CALLBACK(n) { if (n->link_callback) (n->link_callback)(n); }
00070 #else
00071 #define NETIF_LINK_CALLBACK(n) { /* NOP */ }
00072 #endif /* LWIP_NETIF_LINK_CALLBACK */ 
00073 
00074 struct netif *netif_list;
00075 struct netif *netif_default;
00076 
00077 /**
00078  * Add a network interface to the list of lwIP netifs.
00079  *
00080  * @param netif a pre-allocated netif structure
00081  * @param ipaddr IP address for the new netif
00082  * @param netmask network mask for the new netif
00083  * @param gw default gateway IP address for the new netif
00084  * @param state opaque data passed to the new netif
00085  * @param init callback function that initializes the interface
00086  * @param input callback function that is called to pass
00087  * ingress packets up in the protocol layer stack.
00088  *
00089  * @return netif, or NULL if failed.
00090  */
00091 struct netif *
00092 netif_add(struct netif *netif, struct ip_addr *ipaddr, struct ip_addr *netmask,
00093   struct ip_addr *gw,
00094   void *state,
00095   err_t (* init)(struct netif *netif),
00096   err_t (* input)(struct pbuf *p, struct netif *netif))
00097 {
00098   static u8_t netifnum = 0;
00099 
00100   /* reset new interface configuration state */
00101   netif->ip_addr.addr = 0;
00102   netif->netmask.addr = 0;
00103   netif->gw.addr = 0;
00104   netif->flags = 0;
00105 #if LWIP_DHCP
00106   /* netif not under DHCP control by default */
00107   netif->dhcp = NULL;
00108 #endif /* LWIP_DHCP */
00109 #if LWIP_AUTOIP
00110   /* netif not under AutoIP control by default */
00111   netif->autoip = NULL;
00112 #endif /* LWIP_AUTOIP */
00113 #if LWIP_NETIF_STATUS_CALLBACK
00114   netif->status_callback = NULL;
00115 #endif /* LWIP_NETIF_STATUS_CALLBACK */
00116 #if LWIP_NETIF_LINK_CALLBACK
00117   netif->link_callback = NULL;
00118 #endif /* LWIP_NETIF_LINK_CALLBACK */
00119 #if LWIP_IGMP
00120   netif->igmp_mac_filter = NULL;
00121 #endif /* LWIP_IGMP */
00122 #if ENABLE_LOOPBACK
00123   netif->loop_first = NULL;
00124   netif->loop_last = NULL;
00125 #endif /* ENABLE_LOOPBACK */
00126 
00127   /* remember netif specific state information data */
00128   netif->state = state;
00129   netif->num = netifnum++;
00130   netif->input = input;
00131 #if LWIP_NETIF_HWADDRHINT
00132   netif->addr_hint = NULL;
00133 #endif /* LWIP_NETIF_HWADDRHINT*/
00134 #if ENABLE_LOOPBACK && LWIP_LOOPBACK_MAX_PBUFS
00135   netif->loop_cnt_current = 0;
00136 #endif /* ENABLE_LOOPBACK && LWIP_LOOPBACK_MAX_PBUFS */
00137 
00138   netif_set_addr(netif, ipaddr, netmask, gw);
00139 
00140   /* call user specified initialization function for netif */
00141   if (init(netif) != ERR_OK) {
00142     return NULL;
00143   }
00144 
00145   /* add this netif to the list */
00146   netif->next = netif_list;
00147   netif_list = netif;
00148   snmp_inc_iflist();
00149 
00150 #if LWIP_IGMP
00151   /* start IGMP processing */
00152   if (netif->flags & NETIF_FLAG_IGMP) {
00153     igmp_start( netif);
00154   }
00155 #endif /* LWIP_IGMP */
00156 
00157   LWIP_DEBUGF(NETIF_DEBUG, ("netif: added interface %c%c IP addr ",
00158     netif->name[0], netif->name[1]));
00159   ip_addr_debug_print(NETIF_DEBUG, ipaddr);
00160   LWIP_DEBUGF(NETIF_DEBUG, (" netmask "));
00161   ip_addr_debug_print(NETIF_DEBUG, netmask);
00162   LWIP_DEBUGF(NETIF_DEBUG, (" gw "));
00163   ip_addr_debug_print(NETIF_DEBUG, gw);
00164   LWIP_DEBUGF(NETIF_DEBUG, ("\n"));
00165   return netif;
00166 }
00167 
00168 /**
00169  * Change IP address configuration for a network interface (including netmask
00170  * and default gateway).
00171  *
00172  * @param netif the network interface to change
00173  * @param ipaddr the new IP address
00174  * @param netmask the new netmask
00175  * @param gw the new default gateway
00176  */
00177 void
00178 netif_set_addr(struct netif *netif, struct ip_addr *ipaddr, struct ip_addr *netmask,
00179     struct ip_addr *gw)
00180 {
00181   netif_set_ipaddr(netif, ipaddr);
00182   netif_set_netmask(netif, netmask);
00183   netif_set_gw(netif, gw);
00184 }
00185 
00186 /**
00187  * Remove a network interface from the list of lwIP netifs.
00188  *
00189  * @param netif the network interface to remove
00190  */
00191 void netif_remove(struct netif * netif)
00192 {
00193   if ( netif == NULL ) return;
00194 
00195 #if LWIP_IGMP
00196   /* stop IGMP processing */
00197   if (netif->flags & NETIF_FLAG_IGMP) {
00198     igmp_stop( netif);
00199   }
00200 #endif /* LWIP_IGMP */
00201 
00202   snmp_delete_ipaddridx_tree(netif);
00203 
00204   /*  is it the first netif? */
00205   if (netif_list == netif) {
00206     netif_list = netif->next;
00207     snmp_dec_iflist();
00208   }
00209   else {
00210     /*  look for netif further down the list */
00211     struct netif * tmpNetif;
00212     for (tmpNetif = netif_list; tmpNetif != NULL; tmpNetif = tmpNetif->next) {
00213       if (tmpNetif->next == netif) {
00214         tmpNetif->next = netif->next;
00215         snmp_dec_iflist();
00216         break;
00217       }
00218     }
00219     if (tmpNetif == NULL)
00220       return; /*  we didn't find any netif today */
00221   }
00222   /* this netif is default? */
00223   if (netif_default == netif)
00224     /* reset default netif */
00225     netif_set_default(NULL);
00226   LWIP_DEBUGF( NETIF_DEBUG, ("netif_remove: removed netif\n") );
00227 }
00228 
00229 /**
00230  * Find a network interface by searching for its name
00231  *
00232  * @param name the name of the netif (like netif->name) plus concatenated number
00233  * in ascii representation (e.g. 'en0')
00234  */
00235 struct netif *
00236 netif_find(char *name)
00237 {
00238   struct netif *netif;
00239   u8_t num;
00240 
00241   if (name == NULL) {
00242     return NULL;
00243   }
00244 
00245   num = name[2] - '0';
00246 
00247   for(netif = netif_list; netif != NULL; netif = netif->next) {
00248     if (num == netif->num &&
00249        name[0] == netif->name[0] &&
00250        name[1] == netif->name[1]) {
00251       LWIP_DEBUGF(NETIF_DEBUG, ("netif_find: found %c%c\n", name[0], name[1]));
00252       return netif;
00253     }
00254   }
00255   LWIP_DEBUGF(NETIF_DEBUG, ("netif_find: didn't find %c%c\n", name[0], name[1]));
00256   return NULL;
00257 }
00258 
00259 /**
00260  * Change the IP address of a network interface
00261  *
00262  * @param netif the network interface to change
00263  * @param ipaddr the new IP address
00264  *
00265  * @note call netif_set_addr() if you also want to change netmask and
00266  * default gateway
00267  */
00268 void
00269 netif_set_ipaddr(struct netif *netif, struct ip_addr *ipaddr)
00270 {
00271   /* TODO: Handling of obsolete pcbs */
00272   /* See:  http://mail.gnu.org/archive/html/lwip-users/2003-03/msg00118.html */
00273 #if LWIP_TCP
00274   struct tcp_pcb *pcb;
00275   struct tcp_pcb_listen *lpcb;
00276 
00277   /* address is actually being changed? */
00278   if ((ip_addr_cmp(ipaddr, &(netif->ip_addr))) == 0)
00279   {
00280     /* extern struct tcp_pcb *tcp_active_pcbs; defined by tcp.h */
00281     LWIP_DEBUGF(NETIF_DEBUG | 1, ("netif_set_ipaddr: netif address being changed\n"));
00282     pcb = tcp_active_pcbs;
00283     while (pcb != NULL) {
00284       /* PCB bound to current local interface address? */
00285       if (ip_addr_cmp(&(pcb->local_ip), &(netif->ip_addr))) {
00286         /* this connection must be aborted */
00287         struct tcp_pcb *next = pcb->next;
00288         LWIP_DEBUGF(NETIF_DEBUG | 1, ("netif_set_ipaddr: aborting TCP pcb %p\n", (void *)pcb));
00289         tcp_abort(pcb);
00290         pcb = next;
00291       } else {
00292         pcb = pcb->next;
00293       }
00294     }
00295     for (lpcb = tcp_listen_pcbs.listen_pcbs; lpcb != NULL; lpcb = lpcb->next) {
00296       /* PCB bound to current local interface address? */
00297       if ((!(ip_addr_isany(&(lpcb->local_ip)))) &&
00298           (ip_addr_cmp(&(lpcb->local_ip), &(netif->ip_addr)))) {
00299         /* The PCB is listening to the old ipaddr and
00300          * is set to listen to the new one instead */
00301         ip_addr_set(&(lpcb->local_ip), ipaddr);
00302       }
00303     }
00304   }
00305 #endif
00306   snmp_delete_ipaddridx_tree(netif);
00307   snmp_delete_iprteidx_tree(0,netif);
00308   /* set new IP address to netif */
00309   ip_addr_set(&(netif->ip_addr), ipaddr);
00310   snmp_insert_ipaddridx_tree(netif);
00311   snmp_insert_iprteidx_tree(0,netif);
00312 
00313   LWIP_DEBUGF(NETIF_DEBUG | LWIP_DBG_TRACE | LWIP_DBG_STATE | 3, ("netif: IP address of interface %c%c set to %"U16_F".%"U16_F".%"U16_F".%"U16_F"\n",
00314     netif->name[0], netif->name[1],
00315     ip4_addr1(&netif->ip_addr),
00316     ip4_addr2(&netif->ip_addr),
00317     ip4_addr3(&netif->ip_addr),
00318     ip4_addr4(&netif->ip_addr)));
00319 }
00320 
00321 /**
00322  * Change the default gateway for a network interface
00323  *
00324  * @param netif the network interface to change
00325  * @param gw the new default gateway
00326  *
00327  * @note call netif_set_addr() if you also want to change ip address and netmask
00328  */
00329 void
00330 netif_set_gw(struct netif *netif, struct ip_addr *gw)
00331 {
00332   ip_addr_set(&(netif->gw), gw);
00333   LWIP_DEBUGF(NETIF_DEBUG | LWIP_DBG_TRACE | LWIP_DBG_STATE | 3, ("netif: GW address of interface %c%c set to %"U16_F".%"U16_F".%"U16_F".%"U16_F"\n",
00334     netif->name[0], netif->name[1],
00335     ip4_addr1(&netif->gw),
00336     ip4_addr2(&netif->gw),
00337     ip4_addr3(&netif->gw),
00338     ip4_addr4(&netif->gw)));
00339 }
00340 
00341 /**
00342  * Change the netmask of a network interface
00343  *
00344  * @param netif the network interface to change
00345  * @param netmask the new netmask
00346  *
00347  * @note call netif_set_addr() if you also want to change ip address and
00348  * default gateway
00349  */
00350 void
00351 netif_set_netmask(struct netif *netif, struct ip_addr *netmask)
00352 {
00353   snmp_delete_iprteidx_tree(0, netif);
00354   /* set new netmask to netif */
00355   ip_addr_set(&(netif->netmask), netmask);
00356   snmp_insert_iprteidx_tree(0, netif);
00357   LWIP_DEBUGF(NETIF_DEBUG | LWIP_DBG_TRACE | LWIP_DBG_STATE | 3, ("netif: netmask of interface %c%c set to %"U16_F".%"U16_F".%"U16_F".%"U16_F"\n",
00358     netif->name[0], netif->name[1],
00359     ip4_addr1(&netif->netmask),
00360     ip4_addr2(&netif->netmask),
00361     ip4_addr3(&netif->netmask),
00362     ip4_addr4(&netif->netmask)));
00363 }
00364 
00365 /**
00366  * Set a network interface as the default network interface
00367  * (used to output all packets for which no specific route is found)
00368  *
00369  * @param netif the default network interface
00370  */
00371 void
00372 netif_set_default(struct netif *netif)
00373 {
00374   if (netif == NULL)
00375   {
00376     /* remove default route */
00377     snmp_delete_iprteidx_tree(1, netif);
00378   }
00379   else
00380   {
00381     /* install default route */
00382     snmp_insert_iprteidx_tree(1, netif);
00383   }
00384   netif_default = netif;
00385   LWIP_DEBUGF(NETIF_DEBUG, ("netif: setting default interface %c%c\n",
00386            netif ? netif->name[0] : '\'', netif ? netif->name[1] : '\''));
00387 }
00388 
00389 /**
00390  * Bring an interface up, available for processing
00391  * traffic.
00392  * 
00393  * @note: Enabling DHCP on a down interface will make it come
00394  * up once configured.
00395  * 
00396  * @see dhcp_start()
00397  */ 
00398 void netif_set_up(struct netif *netif)
00399 {
00400   if ( !(netif->flags & NETIF_FLAG_UP )) {
00401     netif->flags |= NETIF_FLAG_UP;
00402     
00403 #if LWIP_SNMP
00404     snmp_get_sysuptime(&netif->ts);
00405 #endif /* LWIP_SNMP */
00406 
00407     NETIF_LINK_CALLBACK(netif);
00408     NETIF_STATUS_CALLBACK(netif);
00409 
00410 #if LWIP_ARP
00411     /* For Ethernet network interfaces, we would like to send a "gratuitous ARP" */ 
00412     if (netif->flags & NETIF_FLAG_ETHARP) {
00413       etharp_gratuitous(netif);
00414     }
00415 #endif /* LWIP_ARP */
00416 
00417 #if LWIP_IGMP
00418     /* resend IGMP memberships */
00419     if (netif->flags & NETIF_FLAG_IGMP) {
00420       igmp_report_groups( netif);
00421     }
00422 #endif /* LWIP_IGMP */
00423   }
00424 }
00425 
00426 /**
00427  * Bring an interface down, disabling any traffic processing.
00428  *
00429  * @note: Enabling DHCP on a down interface will make it come
00430  * up once configured.
00431  * 
00432  * @see dhcp_start()
00433  */ 
00434 void netif_set_down(struct netif *netif)
00435 {
00436   if ( netif->flags & NETIF_FLAG_UP )
00437     {
00438       netif->flags &= ~NETIF_FLAG_UP;
00439 #if LWIP_SNMP
00440       snmp_get_sysuptime(&netif->ts);
00441 #endif
00442       
00443       NETIF_LINK_CALLBACK(netif);
00444       NETIF_STATUS_CALLBACK(netif);
00445     }
00446 }
00447 
00448 /**
00449  * Ask if an interface is up
00450  */ 
00451 u8_t netif_is_up(struct netif *netif)
00452 {
00453   return (netif->flags & NETIF_FLAG_UP)?1:0;
00454 }
00455 
00456 #if LWIP_NETIF_STATUS_CALLBACK
00457 /**
00458  * Set callback to be called when interface is brought up/down
00459  */
00460 void netif_set_status_callback(struct netif *netif, void (* status_callback)(struct netif *netif ))
00461 {
00462     if ( netif )
00463         netif->status_callback = status_callback;
00464 }
00465 #endif /* LWIP_NETIF_STATUS_CALLBACK */
00466 
00467 #if LWIP_NETIF_LINK_CALLBACK
00468 /**
00469  * Called by a driver when its link goes up
00470  */
00471 void netif_set_link_up(struct netif *netif )
00472 {
00473   netif->flags |= NETIF_FLAG_LINK_UP;
00474 
00475 #if LWIP_DHCP
00476   if (netif->dhcp) {
00477     dhcp_network_changed(netif);
00478   }
00479 #endif /* LWIP_DHCP */
00480 
00481 #if LWIP_AUTOIP
00482   if (netif->autoip) {
00483     autoip_network_changed(netif);
00484   }
00485 #endif /* LWIP_AUTOIP */
00486 
00487   if (netif->flags & NETIF_FLAG_UP) {
00488 #if LWIP_ARP
00489   /* For Ethernet network interfaces, we would like to send a "gratuitous ARP" */ 
00490   if (netif->flags & NETIF_FLAG_ETHARP) {
00491     etharp_gratuitous(netif);
00492   }
00493 #endif /* LWIP_ARP */
00494 
00495 #if LWIP_IGMP
00496     /* resend IGMP memberships */
00497     if (netif->flags & NETIF_FLAG_IGMP) {
00498       igmp_report_groups( netif);
00499     }
00500 #endif /* LWIP_IGMP */
00501   }
00502   NETIF_LINK_CALLBACK(netif);
00503 }
00504 
00505 /**
00506  * Called by a driver when its link goes down
00507  */
00508 void netif_set_link_down(struct netif *netif )
00509 {
00510   netif->flags &= ~NETIF_FLAG_LINK_UP;
00511   NETIF_LINK_CALLBACK(netif);
00512 }
00513 
00514 /**
00515  * Ask if a link is up
00516  */ 
00517 u8_t netif_is_link_up(struct netif *netif)
00518 {
00519   return (netif->flags & NETIF_FLAG_LINK_UP) ? 1 : 0;
00520 }
00521 
00522 /**
00523  * Set callback to be called when link is brought up/down
00524  */
00525 void netif_set_link_callback(struct netif *netif, void (* link_callback)(struct netif *netif ))
00526 {
00527   if (netif) {
00528     netif->link_callback = link_callback;
00529   }
00530 }
00531 #endif /* LWIP_NETIF_LINK_CALLBACK */
00532 
00533 #if ENABLE_LOOPBACK
00534 /**
00535  * Send an IP packet to be received on the same netif (loopif-like).
00536  * The pbuf is simply copied and handed back to netif->input.
00537  * In multithreaded mode, this is done directly since netif->input must put
00538  * the packet on a queue.
00539  * In callback mode, the packet is put on an internal queue and is fed to
00540  * netif->input by netif_poll().
00541  *
00542  * @param netif the lwip network interface structure
00543  * @param p the (IP) packet to 'send'
00544  * @param ipaddr the ip address to send the packet to (not used)
00545  * @return ERR_OK if the packet has been sent
00546  *         ERR_MEM if the pbuf used to copy the packet couldn't be allocated
00547  */
00548 err_t
00549 netif_loop_output(struct netif *netif, struct pbuf *p,
00550        struct ip_addr *ipaddr)
00551 {
00552   struct pbuf *r;
00553   err_t err;
00554   struct pbuf *last;
00555 #if LWIP_LOOPBACK_MAX_PBUFS
00556   u8_t clen = 0;
00557 #endif /* LWIP_LOOPBACK_MAX_PBUFS */
00558   SYS_ARCH_DECL_PROTECT(lev);
00559   LWIP_UNUSED_ARG(ipaddr);
00560 
00561   /* Allocate a new pbuf */
00562   r = pbuf_alloc(PBUF_LINK, p->tot_len, PBUF_RAM);
00563   if (r == NULL) {
00564     return ERR_MEM;
00565   }
00566 #if LWIP_LOOPBACK_MAX_PBUFS
00567   clen = pbuf_clen(r);
00568   /* check for overflow or too many pbuf on queue */
00569   if(((netif->loop_cnt_current + clen) < netif->loop_cnt_current) ||
00570     ((netif->loop_cnt_current + clen) > LWIP_LOOPBACK_MAX_PBUFS)) {
00571       pbuf_free(r);
00572       r = NULL;
00573       return ERR_MEM;
00574   }
00575   netif->loop_cnt_current += clen;
00576 #endif /* LWIP_LOOPBACK_MAX_PBUFS */
00577 
00578   /* Copy the whole pbuf queue p into the single pbuf r */
00579   if ((err = pbuf_copy(r, p)) != ERR_OK) {
00580     pbuf_free(r);
00581     r = NULL;
00582     return err;
00583   }
00584 
00585   /* Put the packet on a linked list which gets emptied through calling
00586      netif_poll(). */
00587 
00588   /* let last point to the last pbuf in chain r */
00589   for (last = r; last->next != NULL; last = last->next);
00590 
00591   SYS_ARCH_PROTECT(lev);
00592   if(netif->loop_first != NULL) {
00593     LWIP_ASSERT("if first != NULL, last must also be != NULL", netif->loop_last != NULL);
00594     netif->loop_last->next = r;
00595     netif->loop_last = last;
00596   } else {
00597     netif->loop_first = r;
00598     netif->loop_last = last;
00599   }
00600   SYS_ARCH_UNPROTECT(lev);
00601 
00602 #if LWIP_NETIF_LOOPBACK_MULTITHREADING
00603   /* For multithreading environment, schedule a call to netif_poll */
00604   tcpip_callback((void (*)(void *))(netif_poll), netif);
00605 #endif /* LWIP_NETIF_LOOPBACK_MULTITHREADING */
00606 
00607   return ERR_OK;
00608 }
00609 
00610 /**
00611  * Call netif_poll() in the main loop of your application. This is to prevent
00612  * reentering non-reentrant functions like tcp_input(). Packets passed to
00613  * netif_loop_output() are put on a list that is passed to netif->input() by
00614  * netif_poll().
00615  */
00616 void
00617 netif_poll(struct netif *netif)
00618 {
00619   struct pbuf *in;
00620   SYS_ARCH_DECL_PROTECT(lev);
00621 
00622   do {
00623     /* Get a packet from the list. With SYS_LIGHTWEIGHT_PROT=1, this is protected */
00624     SYS_ARCH_PROTECT(lev);
00625     in = netif->loop_first;
00626     if(in != NULL) {
00627       struct pbuf *in_end = in;
00628 #if LWIP_LOOPBACK_MAX_PBUFS
00629       u8_t clen = pbuf_clen(in);
00630       /* adjust the number of pbufs on queue */
00631       LWIP_ASSERT("netif->loop_cnt_current underflow",
00632         ((netif->loop_cnt_current - clen) < netif->loop_cnt_current));
00633       netif->loop_cnt_current -= clen;
00634 #endif /* LWIP_LOOPBACK_MAX_PBUFS */
00635       while(in_end->len != in_end->tot_len) {
00636         LWIP_ASSERT("bogus pbuf: len != tot_len but next == NULL!", in_end->next != NULL);
00637         in_end = in_end->next;
00638       }
00639       /* 'in_end' now points to the last pbuf from 'in' */
00640       if(in_end == netif->loop_last) {
00641         /* this was the last pbuf in the list */
00642         netif->loop_first = netif->loop_last = NULL;
00643       } else {
00644         /* pop the pbuf off the list */
00645         netif->loop_first = in_end->next;
00646         LWIP_ASSERT("should not be null since first != last!", netif->loop_first != NULL);
00647       }
00648       /* De-queue the pbuf from its successors on the 'loop_' list. */
00649       in_end->next = NULL;
00650     }
00651     SYS_ARCH_UNPROTECT(lev);
00652 
00653     if(in != NULL) {
00654       /* loopback packets are always IP packets! */
00655       if(ip_input(in, netif) != ERR_OK) {
00656         pbuf_free(in);
00657       }
00658       /* Don't reference the packet any more! */
00659       in = NULL;
00660     }
00661   /* go on while there is a packet on the list */
00662   } while(netif->loop_first != NULL);
00663 }
00664 
00665 #if !LWIP_NETIF_LOOPBACK_MULTITHREADING
00666 /**
00667  * Calls netif_poll() for every netif on the netif_list.
00668  */
00669 void
00670 netif_poll_all(void)
00671 {
00672   struct netif *netif = netif_list;
00673   /* loop through netifs */
00674   while (netif != NULL) {
00675     netif_poll(netif);
00676     /* proceed to next network interface */
00677     netif = netif->next;
00678   }
00679 }
00680 #endif /* !LWIP_NETIF_LOOPBACK_MULTITHREADING */
00681 #endif /* ENABLE_LOOPBACK */