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 
00049 #if LWIP_NETIF_STATUS_CALLBACK
00050 #define NETIF_STATUS_CALLBACK(n) { if (n->status_callback) (n->status_callback)(n); }
00051 #else
00052 #define NETIF_STATUS_CALLBACK(n) { /* NOP */ }
00053 #endif /* LWIP_NETIF_STATUS_CALLBACK */ 
00054 
00055 #if LWIP_NETIF_LINK_CALLBACK
00056 #define NETIF_LINK_CALLBACK(n) { if (n->link_callback) (n->link_callback)(n); }
00057 #else
00058 #define NETIF_LINK_CALLBACK(n) { /* NOP */ }
00059 #endif /* LWIP_NETIF_LINK_CALLBACK */ 
00060 
00061 struct netif *netif_list;
00062 struct netif *netif_default;
00063 
00064 /**
00065  * Add a network interface to the list of lwIP netifs.
00066  *
00067  * @param netif a pre-allocated netif structure
00068  * @param ipaddr IP address for the new netif
00069  * @param netmask network mask for the new netif
00070  * @param gw default gateway IP address for the new netif
00071  * @param state opaque data passed to the new netif
00072  * @param init callback function that initializes the interface
00073  * @param input callback function that is called to pass
00074  * ingress packets up in the protocol layer stack.
00075  *
00076  * @return netif, or NULL if failed.
00077  */
00078 struct netif *
00079 netif_add(struct netif *netif, struct ip_addr *ipaddr, struct ip_addr *netmask,
00080   struct ip_addr *gw,
00081   void *state,
00082   err_t (* init)(struct netif *netif),
00083   err_t (* input)(struct pbuf *p, struct netif *netif))
00084 {
00085   static u8_t netifnum = 0;
00086 
00087   /* reset new interface configuration state */
00088   netif->ip_addr.addr = 0;
00089   netif->netmask.addr = 0;
00090   netif->gw.addr = 0;
00091   netif->flags = 0;
00092 #if LWIP_DHCP
00093   /* netif not under DHCP control by default */
00094   netif->dhcp = NULL;
00095 #endif /* LWIP_DHCP */
00096 #if LWIP_AUTOIP
00097   /* netif not under AutoIP control by default */
00098   netif->autoip = NULL;
00099 #endif /* LWIP_AUTOIP */
00100 #if LWIP_NETIF_STATUS_CALLBACK
00101   netif->status_callback = NULL;
00102 #endif /* LWIP_NETIF_STATUS_CALLBACK */
00103 #if LWIP_NETIF_LINK_CALLBACK
00104   netif->link_callback = NULL;
00105 #endif /* LWIP_NETIF_LINK_CALLBACK */
00106 #if LWIP_IGMP
00107   netif->igmp_mac_filter = NULL;
00108 #endif /* LWIP_IGMP */
00109 
00110   /* remember netif specific state information data */
00111   netif->state = state;
00112   netif->num = netifnum++;
00113   netif->input = input;
00114 #if LWIP_NETIF_HWADDRHINT
00115   netif->addr_hint = NULL;
00116 #endif /* LWIP_NETIF_HWADDRHINT*/
00117 
00118   netif_set_addr(netif, ipaddr, netmask, gw);
00119 
00120   /* call user specified initialization function for netif */
00121   if (init(netif) != ERR_OK) {
00122     return static_cast<struct netif *>(NULL);
00123   }
00124 
00125   /* add this netif to the list */
00126   netif->next = netif_list;
00127   netif_list = netif;
00128   snmp_inc_iflist();
00129 
00130 #if LWIP_IGMP
00131   /* start IGMP processing */
00132   if (netif->flags & NETIF_FLAG_IGMP) {
00133     igmp_start( netif);
00134   }
00135 #endif /* LWIP_IGMP */
00136 
00137   LWIP_DEBUGF(NETIF_DEBUG, ("netif: added interface %c%c IP addr ",
00138     netif->name[0], netif->name[1]));
00139   ip_addr_debug_print(NETIF_DEBUG, ipaddr);
00140   LWIP_DEBUGF(NETIF_DEBUG, (" netmask "));
00141   ip_addr_debug_print(NETIF_DEBUG, netmask);
00142   LWIP_DEBUGF(NETIF_DEBUG, (" gw "));
00143   ip_addr_debug_print(NETIF_DEBUG, gw);
00144   LWIP_DEBUGF(NETIF_DEBUG, ("\n"));
00145   return netif;
00146 }
00147 
00148 /**
00149  * Change IP address configuration for a network interface (including netmask
00150  * and default gateway).
00151  *
00152  * @param netif the network interface to change
00153  * @param ipaddr the new IP address
00154  * @param netmask the new netmask
00155  * @param gw the new default gateway
00156  */
00157 void
00158 netif_set_addr(struct netif *netif, struct ip_addr *ipaddr, struct ip_addr *netmask,
00159     struct ip_addr *gw)
00160 {
00161   netif_set_ipaddr(netif, ipaddr);
00162   netif_set_netmask(netif, netmask);
00163   netif_set_gw(netif, gw);
00164 }
00165 
00166 /**
00167  * Remove a network interface from the list of lwIP netifs.
00168  *
00169  * @param netif the network interface to remove
00170  */
00171 void netif_remove(struct netif * netif)
00172 {
00173   if ( netif == NULL ) return;
00174 
00175 #if LWIP_IGMP
00176   /* stop IGMP processing */
00177   if (netif->flags & NETIF_FLAG_IGMP) {
00178     igmp_stop( netif);
00179   }
00180 #endif /* LWIP_IGMP */
00181 
00182   snmp_delete_ipaddridx_tree(netif);
00183 
00184   /*  is it the first netif? */
00185   if (netif_list == netif) {
00186     netif_list = netif->next;
00187     snmp_dec_iflist();
00188   }
00189   else {
00190     /*  look for netif further down the list */
00191     struct netif * tmpNetif;
00192     for (tmpNetif = netif_list; tmpNetif != NULL; tmpNetif = tmpNetif->next) {
00193       if (tmpNetif->next == netif) {
00194         tmpNetif->next = netif->next;
00195         snmp_dec_iflist();
00196         break;
00197       }
00198     }
00199     if (tmpNetif == NULL)
00200       return; /*  we didn't find any netif today */
00201   }
00202   /* this netif is default? */
00203   if (netif_default == netif)
00204     /* reset default netif */
00205     netif_set_default(static_cast<struct netif *>(NULL));
00206   LWIP_DEBUGF( NETIF_DEBUG, ("netif_remove: removed netif\n") );
00207 }
00208 
00209 /**
00210  * Find a network interface by searching for its name
00211  *
00212  * @param name the name of the netif (like netif->name) plus concatenated number
00213  * in ascii representation (e.g. 'en0')
00214  */
00215 struct netif *
00216 netif_find(char *name)
00217 {
00218   struct netif *netif;
00219   u8_t num;
00220 
00221   if (name == NULL) {
00222     return static_cast<struct netif *>(NULL);
00223   }
00224 
00225   num = name[2] - '0';
00226 
00227   for(netif = netif_list; netif != NULL; netif = netif->next) {
00228     if (num == netif->num &&
00229        name[0] == netif->name[0] &&
00230        name[1] == netif->name[1]) {
00231       LWIP_DEBUGF(NETIF_DEBUG, ("netif_find: found %c%c\n", name[0], name[1]));
00232       return netif;
00233     }
00234   }
00235   LWIP_DEBUGF(NETIF_DEBUG, ("netif_find: didn't find %c%c\n", name[0], name[1]));
00236   return static_cast<struct netif *>(NULL);
00237 }
00238 
00239 /**
00240  * Change the IP address of a network interface
00241  *
00242  * @param netif the network interface to change
00243  * @param ipaddr the new IP address
00244  *
00245  * @note call netif_set_addr() if you also want to change netmask and
00246  * default gateway
00247  */
00248 void
00249 netif_set_ipaddr(struct netif *netif, struct ip_addr *ipaddr)
00250 {
00251   /* TODO: Handling of obsolete pcbs */
00252   /* See:  http://mail.gnu.org/archive/html/lwip-users/2003-03/msg00118.html */
00253 #if LWIP_TCP
00254   struct tcp_pcb *pcb;
00255   struct tcp_pcb_listen *lpcb;
00256 
00257   /* address is actually being changed? */
00258   if ((ip_addr_cmp(ipaddr, &(netif->ip_addr))) == 0)
00259   {
00260     /* extern struct tcp_pcb *tcp_active_pcbs; defined by tcp.h */
00261     LWIP_DEBUGF(NETIF_DEBUG | 1, ("netif_set_ipaddr: netif address being changed\n"));
00262     pcb = tcp_active_pcbs;
00263     while (pcb != NULL) {
00264       /* PCB bound to current local interface address? */
00265       if (ip_addr_cmp(&(pcb->local_ip), &(netif->ip_addr))) {
00266         /* this connection must be aborted */
00267         struct tcp_pcb *next = pcb->next;
00268         LWIP_DEBUGF(NETIF_DEBUG | 1, ("netif_set_ipaddr: aborting TCP pcb %p\n", (void *)pcb));
00269         tcp_abort(pcb);
00270         pcb = next;
00271       } else {
00272         pcb = pcb->next;
00273       }
00274     }
00275     for (lpcb = tcp_listen_pcbs.listen_pcbs; lpcb != NULL; lpcb = lpcb->next) {
00276       /* PCB bound to current local interface address? */
00277       if ((!(ip_addr_isany(&(lpcb->local_ip)))) &&
00278           (ip_addr_cmp(&(lpcb->local_ip), &(netif->ip_addr)))) {
00279         /* The PCB is listening to the old ipaddr and
00280          * is set to listen to the new one instead */
00281         ip_addr_set(&(lpcb->local_ip), ipaddr);
00282       }
00283     }
00284   }
00285 #endif
00286   snmp_delete_ipaddridx_tree(netif);
00287   snmp_delete_iprteidx_tree(0,netif);
00288   /* set new IP address to netif */
00289   ip_addr_set(&(netif->ip_addr), ipaddr);
00290   snmp_insert_ipaddridx_tree(netif);
00291   snmp_insert_iprteidx_tree(0,netif);
00292 
00293   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",
00294     netif->name[0], netif->name[1],
00295     ip4_addr1(&netif->ip_addr),
00296     ip4_addr2(&netif->ip_addr),
00297     ip4_addr3(&netif->ip_addr),
00298     ip4_addr4(&netif->ip_addr)));
00299 }
00300 
00301 /**
00302  * Change the default gateway for a network interface
00303  *
00304  * @param netif the network interface to change
00305  * @param gw the new default gateway
00306  *
00307  * @note call netif_set_addr() if you also want to change ip address and netmask
00308  */
00309 void
00310 netif_set_gw(struct netif *netif, struct ip_addr *gw)
00311 {
00312   ip_addr_set(&(netif->gw), gw);
00313   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",
00314     netif->name[0], netif->name[1],
00315     ip4_addr1(&netif->gw),
00316     ip4_addr2(&netif->gw),
00317     ip4_addr3(&netif->gw),
00318     ip4_addr4(&netif->gw)));
00319 }
00320 
00321 /**
00322  * Change the netmask of a network interface
00323  *
00324  * @param netif the network interface to change
00325  * @param netmask the new netmask
00326  *
00327  * @note call netif_set_addr() if you also want to change ip address and
00328  * default gateway
00329  */
00330 void
00331 netif_set_netmask(struct netif *netif, struct ip_addr *netmask)
00332 {
00333   snmp_delete_iprteidx_tree(0, netif);
00334   /* set new netmask to netif */
00335   ip_addr_set(&(netif->netmask), netmask);
00336   snmp_insert_iprteidx_tree(0, netif);
00337   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",
00338     netif->name[0], netif->name[1],
00339     ip4_addr1(&netif->netmask),
00340     ip4_addr2(&netif->netmask),
00341     ip4_addr3(&netif->netmask),
00342     ip4_addr4(&netif->netmask)));
00343 }
00344 
00345 /**
00346  * Set a network interface as the default network interface
00347  * (used to output all packets for which no specific route is found)
00348  *
00349  * @param netif the default network interface
00350  */
00351 void
00352 netif_set_default(struct netif *netif)
00353 {
00354   if (netif == NULL)
00355   {
00356     /* remove default route */
00357     snmp_delete_iprteidx_tree(1, netif);
00358   }
00359   else
00360   {
00361     /* install default route */
00362     snmp_insert_iprteidx_tree(1, netif);
00363   }
00364   netif_default = netif;
00365   LWIP_DEBUGF(NETIF_DEBUG, ("netif: setting default interface %c%c\n",
00366            netif ? netif->name[0] : '\'', netif ? netif->name[1] : '\''));
00367 }
00368 
00369 /**
00370  * Bring an interface up, available for processing
00371  * traffic.
00372  * 
00373  * @note: Enabling DHCP on a down interface will make it come
00374  * up once configured.
00375  * 
00376  * @see dhcp_start()
00377  */ 
00378 void netif_set_up(struct netif *netif)
00379 {
00380   if ( !(netif->flags & NETIF_FLAG_UP )) {
00381     netif->flags |= NETIF_FLAG_UP;
00382     
00383 #if LWIP_SNMP
00384     snmp_get_sysuptime(&netif->ts);
00385 #endif /* LWIP_SNMP */
00386 
00387     NETIF_LINK_CALLBACK(netif);
00388     NETIF_STATUS_CALLBACK(netif);
00389 
00390 #if LWIP_ARP
00391     /** For Ethernet network interfaces, we would like to send a
00392      *  "gratuitous ARP"; this is an ARP packet sent by a node in order
00393      *  to spontaneously cause other nodes to update an entry in their
00394      *  ARP cache. From RFC 3220 "IP Mobility Support for IPv4" section 4.6.
00395      */ 
00396     if (netif->flags & NETIF_FLAG_ETHARP) {
00397       etharp_query(netif, &(netif->ip_addr), static_cast<struct pbuf *>(NULL));
00398     }
00399 #endif /* LWIP_ARP */
00400     
00401   }
00402 }
00403 
00404 /**
00405  * Bring an interface down, disabling any traffic processing.
00406  *
00407  * @note: Enabling DHCP on a down interface will make it come
00408  * up once configured.
00409  * 
00410  * @see dhcp_start()
00411  */ 
00412 void netif_set_down(struct netif *netif)
00413 {
00414   if ( netif->flags & NETIF_FLAG_UP )
00415     {
00416       netif->flags &= ~NETIF_FLAG_UP;
00417 #if LWIP_SNMP
00418       snmp_get_sysuptime(&netif->ts);
00419 #endif
00420       
00421       NETIF_LINK_CALLBACK(netif);
00422       NETIF_STATUS_CALLBACK(netif);
00423     }
00424 }
00425 
00426 /**
00427  * Ask if an interface is up
00428  */ 
00429 u8_t netif_is_up(struct netif *netif)
00430 {
00431   return (netif->flags & NETIF_FLAG_UP)?1:0;
00432 }
00433 
00434 #if LWIP_NETIF_STATUS_CALLBACK
00435 /**
00436  * Set callback to be called when interface is brought up/down
00437  */
00438 void netif_set_status_callback(struct netif *netif, void (* status_callback)(struct netif *netif ))
00439 {
00440     if ( netif )
00441         netif->status_callback = status_callback;
00442 }
00443 #endif /* LWIP_NETIF_STATUS_CALLBACK */
00444 
00445 #if LWIP_NETIF_LINK_CALLBACK
00446 /**
00447  * Called by a driver when its link goes up
00448  */
00449 void netif_set_link_up(struct netif *netif )
00450 {
00451   netif->flags |= NETIF_FLAG_LINK_UP;
00452 
00453 #if LWIP_ARP
00454   /** For Ethernet network interfaces, we would like to send a
00455    *  "gratuitous ARP"; this is an ARP packet sent by a node in order
00456    *  to spontaneously cause other nodes to update an entry in their
00457    *  ARP cache. From RFC 3220 "IP Mobility Support for IPv4" section 4.6.
00458    */ 
00459   if (netif->flags & NETIF_FLAG_ETHARP) {
00460     etharp_query(netif, &(netif->ip_addr), NULL);
00461   }
00462 #endif /* LWIP_ARP */
00463 
00464 #if LWIP_IGMP
00465   /* resend IGMP memberships */
00466   if (netif->flags & NETIF_FLAG_IGMP) {
00467     igmp_report_groups( netif);
00468   }
00469 #endif /* LWIP_IGMP */
00470 
00471   NETIF_LINK_CALLBACK(netif);
00472 }
00473 
00474 /**
00475  * Called by a driver when its link goes down
00476  */
00477 void netif_set_link_down(struct netif *netif )
00478 {
00479   netif->flags &= ~NETIF_FLAG_LINK_UP;
00480   NETIF_LINK_CALLBACK(netif);
00481 }
00482 
00483 /**
00484  * Ask if a link is up
00485  */ 
00486 u8_t netif_is_link_up(struct netif *netif)
00487 {
00488   return (netif->flags & NETIF_FLAG_LINK_UP) ? 1 : 0;
00489 }
00490 
00491 /**
00492  * Set callback to be called when link is brought up/down
00493  */
00494 void netif_set_link_callback(struct netif *netif, void (* link_callback)(struct netif *netif ))
00495 {
00496     if ( netif )
00497         netif->link_callback = link_callback;
00498 }
00499 #endif /* LWIP_NETIF_LINK_CALLBACK */