1 /* net/if.h -- declarations for inquiring about network interfaces 2 Copyright (C) 1997-2022 Free Software Foundation, Inc. 3 This file is part of the GNU C Library. 4 5 The GNU C Library is free software; you can redistribute it and/or 6 modify it under the terms of the GNU Lesser General Public 7 License as published by the Free Software Foundation; either 8 version 2.1 of the License, or (at your option) any later version. 9 10 The GNU C Library is distributed in the hope that it will be useful, 11 but WITHOUT ANY WARRANTY; without even the implied warranty of 12 MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the GNU 13 Lesser General Public License for more details. 14 15 You should have received a copy of the GNU Lesser General Public 16 License along with the GNU C Library; if not, see 17 <https://www.gnu.org/licenses/>. */ 18 19 #ifndef _NET_IF_H 20 #define _NET_IF_H 1 21 22 #include <features.h> 23 24 #ifdef __USE_MISC 25 # include <sys/types.h> 26 # include <sys/socket.h> 27 #endif 28 29 30 /* Length of interface name. */ 31 #define IF_NAMESIZE 16 32 33 struct if_nameindex 34 { 35 unsigned int if_index; /* 1, 2, ... */ 36 char *if_name; /* null terminated name: "eth0", ... */ 37 }; 38 39 40 #ifdef __USE_MISC 41 /* Standard interface flags. */ 42 enum 43 { 44 IFF_UP = 0x1, /* Interface is up. */ 45 # define IFF_UP IFF_UP 46 IFF_BROADCAST = 0x2, /* Broadcast address valid. */ 47 # define IFF_BROADCAST IFF_BROADCAST 48 IFF_DEBUG = 0x4, /* Turn on debugging. */ 49 # define IFF_DEBUG IFF_DEBUG 50 IFF_LOOPBACK = 0x8, /* Is a loopback net. */ 51 # define IFF_LOOPBACK IFF_LOOPBACK 52 IFF_POINTOPOINT = 0x10, /* Interface is point-to-point link. */ 53 # define IFF_POINTOPOINT IFF_POINTOPOINT 54 IFF_NOTRAILERS = 0x20, /* Avoid use of trailers. */ 55 # define IFF_NOTRAILERS IFF_NOTRAILERS 56 IFF_RUNNING = 0x40, /* Resources allocated. */ 57 # define IFF_RUNNING IFF_RUNNING 58 IFF_NOARP = 0x80, /* No address resolution protocol. */ 59 # define IFF_NOARP IFF_NOARP 60 IFF_PROMISC = 0x100, /* Receive all packets. */ 61 # define IFF_PROMISC IFF_PROMISC 62 63 /* Not supported */ 64 IFF_ALLMULTI = 0x200, /* Receive all multicast packets. */ 65 # define IFF_ALLMULTI IFF_ALLMULTI 66 67 IFF_MASTER = 0x400, /* Master of a load balancer. */ 68 # define IFF_MASTER IFF_MASTER 69 IFF_SLAVE = 0x800, /* Slave of a load balancer. */ 70 # define IFF_SLAVE IFF_SLAVE 71 72 IFF_MULTICAST = 0x1000, /* Supports multicast. */ 73 # define IFF_MULTICAST IFF_MULTICAST 74 75 IFF_PORTSEL = 0x2000, /* Can set media type. */ 76 # define IFF_PORTSEL IFF_PORTSEL 77 IFF_AUTOMEDIA = 0x4000, /* Auto media select active. */ 78 # define IFF_AUTOMEDIA IFF_AUTOMEDIA 79 IFF_DYNAMIC = 0x8000 /* Dialup device with changing addresses. */ 80 # define IFF_DYNAMIC IFF_DYNAMIC 81 }; 82 83 /* The ifaddr structure contains information about one address of an 84 interface. They are maintained by the different address families, 85 are allocated and attached when an address is set, and are linked 86 together so all addresses for an interface can be located. */ 87 88 struct ifaddr 89 { 90 struct sockaddr ifa_addr; /* Address of interface. */ 91 union 92 { 93 struct sockaddr ifu_broadaddr; 94 struct sockaddr ifu_dstaddr; 95 } ifa_ifu; 96 struct iface *ifa_ifp; /* Back-pointer to interface. */ 97 struct ifaddr *ifa_next; /* Next address for interface. */ 98 }; 99 100 # define ifa_broadaddr ifa_ifu.ifu_broadaddr /* broadcast address */ 101 # define ifa_dstaddr ifa_ifu.ifu_dstaddr /* other end of link */ 102 103 /* Device mapping structure. I'd just gone off and designed a 104 beautiful scheme using only loadable modules with arguments for 105 driver options and along come the PCMCIA people 8) 106 107 Ah well. The get() side of this is good for WDSETUP, and it'll be 108 handy for debugging things. The set side is fine for now and being 109 very small might be worth keeping for clean configuration. */ 110 111 struct ifmap 112 { 113 unsigned long int mem_start; 114 unsigned long int mem_end; 115 unsigned short int base_addr; 116 unsigned char irq; 117 unsigned char dma; 118 unsigned char port; 119 /* 3 bytes spare */ 120 }; 121 122 /* Interface request structure used for socket ioctl's. All interface 123 ioctl's must have parameter definitions which begin with ifr_name. 124 The remainder may be interface specific. */ 125 126 struct ifreq 127 { 128 # define IFHWADDRLEN 6 129 # define IFNAMSIZ IF_NAMESIZE 130 union 131 { 132 char ifrn_name[IFNAMSIZ]; /* Interface name, e.g. "en0". */ 133 } ifr_ifrn; 134 135 union 136 { 137 struct sockaddr ifru_addr; 138 struct sockaddr ifru_dstaddr; 139 struct sockaddr ifru_broadaddr; 140 struct sockaddr ifru_netmask; 141 struct sockaddr ifru_hwaddr; 142 short int ifru_flags; 143 int ifru_ivalue; 144 int ifru_mtu; 145 struct ifmap ifru_map; 146 char ifru_slave[IFNAMSIZ]; /* Just fits the size */ 147 char ifru_newname[IFNAMSIZ]; 148 __caddr_t ifru_data; 149 } ifr_ifru; 150 }; 151 # define ifr_name ifr_ifrn.ifrn_name /* interface name */ 152 # define ifr_hwaddr ifr_ifru.ifru_hwaddr /* MAC address */ 153 # define ifr_addr ifr_ifru.ifru_addr /* address */ 154 # define ifr_dstaddr ifr_ifru.ifru_dstaddr /* other end of p-p lnk */ 155 # define ifr_broadaddr ifr_ifru.ifru_broadaddr /* broadcast address */ 156 # define ifr_netmask ifr_ifru.ifru_netmask /* interface net mask */ 157 # define ifr_flags ifr_ifru.ifru_flags /* flags */ 158 # define ifr_metric ifr_ifru.ifru_ivalue /* metric */ 159 # define ifr_mtu ifr_ifru.ifru_mtu /* mtu */ 160 # define ifr_map ifr_ifru.ifru_map /* device map */ 161 # define ifr_slave ifr_ifru.ifru_slave /* slave device */ 162 # define ifr_data ifr_ifru.ifru_data /* for use by interface */ 163 # define ifr_ifindex ifr_ifru.ifru_ivalue /* interface index */ 164 # define ifr_bandwidth ifr_ifru.ifru_ivalue /* link bandwidth */ 165 # define ifr_qlen ifr_ifru.ifru_ivalue /* queue length */ 166 # define ifr_newname ifr_ifru.ifru_newname /* New name */ 167 # define _IOT_ifreq _IOT(_IOTS(char),IFNAMSIZ,_IOTS(char),16,0,0) 168 # define _IOT_ifreq_short _IOT(_IOTS(char),IFNAMSIZ,_IOTS(short),1,0,0) 169 # define _IOT_ifreq_int _IOT(_IOTS(char),IFNAMSIZ,_IOTS(int),1,0,0) 170 171 172 /* Structure used in SIOCGIFCONF request. Used to retrieve interface 173 configuration for machine (useful for programs which must know all 174 networks accessible). */ 175 176 struct ifconf 177 { 178 int ifc_len; /* Size of buffer. */ 179 union 180 { 181 __caddr_t ifcu_buf; 182 struct ifreq *ifcu_req; 183 } ifc_ifcu; 184 }; 185 # define ifc_buf ifc_ifcu.ifcu_buf /* Buffer address. */ 186 # define ifc_req ifc_ifcu.ifcu_req /* Array of structures. */ 187 # define _IOT_ifconf _IOT(_IOTS(struct ifconf),1,0,0,0,0) /* not right */ 188 #endif /* Misc. */ 189 190 __BEGIN_DECLS 191 192 /* Convert an interface name to an index, and vice versa. */ 193 extern unsigned int if_nametoindex (const char *__ifname) __THROW; 194 extern char *if_indextoname (unsigned int __ifindex, 195 char __ifname[IF_NAMESIZE]) __THROW 196 __attr_access ((__write_only__, 2)); 197 198 /* Return a list of all interfaces and their indices. */ 199 extern struct if_nameindex *if_nameindex (void) __THROW; 200 201 /* Free the data returned from if_nameindex. */ 202 extern void if_freenameindex (struct if_nameindex *__ptr) __THROW; 203 204 __END_DECLS 205 206 #endif /* net/if.h */ 207