1 /* $NetBSD: if_nameindex.c,v 1.2 2000/04/24 10:40:25 itojun Exp $ */ 2 /* $KAME: if_nameindex.c,v 1.3 2000/04/24 10:08:41 itojun Exp $ */ 3 4 /*- 5 * Copyright (c) 1997, 2000 6 * Berkeley Software Design, Inc. All rights reserved. 7 * 8 * Redistribution and use in source and binary forms, with or without 9 * modification, are permitted provided that the following conditions 10 * are met: 11 * 1. Redistributions of source code must retain the above copyright 12 * notice, this list of conditions and the following disclaimer. 13 * 14 * THIS SOFTWARE IS PROVIDED BY Berkeley Software Design, Inc. ``AS IS'' AND 15 * ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE 16 * IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE 17 * ARE DISCLAIMED. IN NO EVENT SHALL Berkeley Software Design, Inc. BE LIABLE 18 * FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL 19 * DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS 20 * OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION) 21 * HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT 22 * LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY 23 * OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF 24 * SUCH DAMAGE. 25 * 26 * BSDI Id: if_nameindex.c,v 2.3 2000/04/17 22:38:05 dab Exp 27 */ 28 29 #include <sys/cdefs.h> 30 #if defined(LIBC_SCCS) && !defined(lint) 31 __RCSID("$NetBSD: if_nameindex.c,v 1.2 2000/04/24 10:40:25 itojun Exp $"); 32 #endif /* LIBC_SCCS and not lint */ 33 34 #include "namespace.h" 35 #include <sys/types.h> 36 #include <sys/socket.h> 37 #include <net/if_dl.h> 38 #include <net/if.h> 39 #include <ifaddrs.h> 40 #include <stdlib.h> 41 #include <string.h> 42 43 #ifdef __weak_alias 44 __weak_alias(if_nameindex,_if_nameindex) 45 __weak_alias(if_freenameindex,_if_freenameindex) 46 #endif 47 /* 48 * From RFC 2133: 49 * 50 * 4.3. Return All Interface Names and Indexes 51 * 52 * The final function returns an array of if_nameindex structures, one 53 * structure per interface. 54 * 55 * #include <net/if.h> 56 * 57 * struct if_nameindex { 58 * unsigned int if_index; / * 1, 2, ... * / 59 * char *if_name; / * null terminated name: "le0", ... * / 60 * }; 61 * 62 * struct if_nameindex *if_nameindex(void); 63 * 64 * The end of the array of structures is indicated by a structure with 65 * an if_index of 0 and an if_name of NULL. The function returns a NULL 66 * pointer upon an error. 67 * 68 * The memory used for this array of structures along with the interface 69 * names pointed to by the if_name members is obtained dynamically. 70 * This memory is freed by the next function. 71 * 72 * 4.4. Free Memory 73 * 74 * The following function frees the dynamic memory that was allocated by 75 * if_nameindex(). 76 * 77 * #include <net/if.h> 78 * 79 * void if_freenameindex(struct if_nameindex *ptr); 80 * 81 * The argument to this function must be a pointer that was returned by 82 * if_nameindex(). 83 */ 84 85 struct if_nameindex * 86 if_nameindex(void) 87 { 88 struct ifaddrs *ifaddrs, *ifa; 89 unsigned int ni; 90 int nbytes; 91 struct if_nameindex *ifni, *ifni2; 92 char *cp; 93 94 if (getifaddrs(&ifaddrs) < 0) 95 return(NULL); 96 97 /* 98 * First, find out how many interfaces there are, and how 99 * much space we need for the string names. 100 */ 101 ni = 0; 102 nbytes = 0; 103 for (ifa = ifaddrs; ifa != NULL; ifa = ifa->ifa_next) { 104 if (ifa->ifa_addr && 105 ifa->ifa_addr->sa_family == AF_LINK) { 106 nbytes += strlen(ifa->ifa_name) + 1; 107 ni++; 108 } 109 } 110 111 /* 112 * Next, allocate a chunk of memory, use the first part 113 * for the array of structures, and the last part for 114 * the strings. 115 */ 116 cp = malloc(ni*(sizeof(struct if_nameindex) + 1) + nbytes); 117 ifni = (struct if_nameindex *)cp; 118 if (ifni == NULL) 119 goto out; 120 cp += ni*(sizeof(struct if_nameindex) + 1); 121 122 /* 123 * Now just loop through the list of interfaces again, 124 * filling in the if_nameindex array and making copies 125 * of all the strings. 126 */ 127 ifni2 = ifni; 128 for (ifa = ifaddrs; ifa != NULL; ifa = ifa->ifa_next) { 129 if (ifa->ifa_addr && 130 ifa->ifa_addr->sa_family == AF_LINK) { 131 ifni2->if_index = 132 ((struct sockaddr_dl*)ifa->ifa_addr)->sdl_index; 133 ifni2->if_name = cp; 134 strcpy(cp, ifa->ifa_name); 135 ifni2++; 136 cp += strlen(cp) + 1; 137 } 138 } 139 /* 140 * Finally, don't forget to terminate the array. 141 */ 142 ifni2->if_index = 0; 143 ifni2->if_name = NULL; 144 out: 145 freeifaddrs(ifaddrs); 146 return(ifni); 147 } 148 149 void 150 if_freenameindex(struct if_nameindex *ptr) 151 { 152 free(ptr); 153 } 154