1 /* $KAME: if_nameindex.c,v 1.8 2000/11/24 08:20:01 itojun Exp $ */
4 * SPDX-License-Identifier: BSD-1-Clause
6 * Copyright (c) 1997, 2000
7 * Berkeley Software Design, Inc. All rights reserved.
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10 * modification, are permitted provided that the following conditions
12 * 1. Redistributions of source code must retain the above copyright
13 * notice, this list of conditions and the following disclaimer.
15 * THIS SOFTWARE IS PROVIDED BY Berkeley Software Design, Inc. ``AS IS'' AND
16 * ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE
17 * IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE
18 * ARE DISCLAIMED. IN NO EVENT SHALL Berkeley Software Design, Inc. BE LIABLE
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20 * DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS
21 * OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION)
22 * HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT
23 * LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY
24 * OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF
27 * BSDI Id: if_nameindex.c,v 2.3 2000/04/17 22:38:05 dab Exp
30 #include <sys/cdefs.h>
31 __FBSDID("$FreeBSD$");
33 #include <sys/types.h>
34 #include <sys/socket.h>
35 #include <net/if_dl.h>
44 * 4.3 Return All Interface Names and Indexes
46 * The if_nameindex structure holds the information about a single
47 * interface and is defined as a result of including the <net/if.h>
50 * struct if_nameindex {
51 * unsigned int if_index;
55 * The final function returns an array of if_nameindex structures, one
56 * structure per interface.
58 * struct if_nameindex *if_nameindex(void);
60 * The end of the array of structures is indicated by a structure with
61 * an if_index of 0 and an if_name of NULL. The function returns a NULL
62 * pointer upon an error, and would set errno to the appropriate value.
64 * The memory used for this array of structures along with the interface
65 * names pointed to by the if_name members is obtained dynamically.
66 * This memory is freed by the next function.
70 * The following function frees the dynamic memory that was allocated by
75 * void if_freenameindex(struct if_nameindex *ptr);
77 * The argument to this function must be a pointer that was returned by
84 struct ifaddrs *ifaddrs, *ifa;
87 struct if_nameindex *ifni, *ifni2;
90 if (getifaddrs(&ifaddrs) < 0)
94 * First, find out how many interfaces there are, and how
95 * much space we need for the string names.
99 for (ifa = ifaddrs; ifa != NULL; ifa = ifa->ifa_next) {
101 ifa->ifa_addr->sa_family == AF_LINK) {
102 nbytes += strlen(ifa->ifa_name) + 1;
108 * Next, allocate a chunk of memory, use the first part
109 * for the array of structures, and the last part for
112 cp = malloc((ni + 1) * sizeof(struct if_nameindex) + nbytes);
113 ifni = (struct if_nameindex *)cp;
116 cp += (ni + 1) * sizeof(struct if_nameindex);
119 * Now just loop through the list of interfaces again,
120 * filling in the if_nameindex array and making copies
121 * of all the strings.
124 for (ifa = ifaddrs; ifa != NULL; ifa = ifa->ifa_next) {
126 ifa->ifa_addr->sa_family == AF_LINK) {
128 LLINDEX((struct sockaddr_dl*)ifa->ifa_addr);
130 strcpy(cp, ifa->ifa_name);
132 cp += strlen(cp) + 1;
136 * Finally, don't forget to terminate the array.
139 ifni2->if_name = NULL;
141 freeifaddrs(ifaddrs);
146 if_freenameindex(struct if_nameindex *ptr)