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Use BSDi derived if_nametoindex(), if_indextoname(), if_nameindex()

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and if_freenameindex().

Obtained from:	KAME
MFC after:	2 weeks
This commit is contained in:
Hajimu UMEMOTO 2002-07-15 19:58:56 +00:00
parent e812f24f6d
commit 8071d8d70d
6 changed files with 406 additions and 331 deletions
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2
lib/libc/net/Makefile.inc
View File

@ -10,7 +10,7 @@ SRCS+= addr2ascii.c ascii2addr.c base64.c ether_addr.c getaddrinfo.c \
getnetbydns.c getnetbyht.c getnetbynis.c getnetnamadr.c \
getproto.c getprotoent.c getprotoname.c getservbyname.c \
getservbyport.c getservent.c herror.c hesiod.c inet_addr.c \
ifname.c inet_lnaof.c \
if_indextoname.c if_nameindex.c if_nametoindex.c inet_lnaof.c \
inet_makeaddr.c inet_net_ntop.c inet_net_pton.c inet_neta.c \
inet_netof.c inet_network.c inet_ntoa.c inet_ntop.c \
inet_pton.c ip6opt.c linkaddr.c map_v4v6.c name6.c ns_addr.c \

181
lib/libc/net/if_indextoname.3
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@ -1,26 +1,19 @@
.\" Copyright (c) 1983, 1991, 1993
.\" The Regents of the University of California. All rights reserved.
.\" $KAME: if_indextoname.3,v 1.10 2000/11/24 08:13:51 itojun Exp $
.\" BSDI Id: if_indextoname.3,v 2.2 2000/04/17 22:38:05 dab Exp
.\"
.\" Copyright (c) 1997, 2000
.\" Berkeley Software Design, Inc. All rights reserved.
.\"
.\" Redistribution and use in source and binary forms, with or without
.\" modification, are permitted provided that the following conditions
.\" are met:
.\" 1. Redistributions of source code must retain the above copyright
.\" notice, this list of conditions and the following disclaimer.
.\" 2. Redistributions in binary form must reproduce the above copyright
.\" notice, this list of conditions and the following disclaimer in the
.\" documentation and/or other materials provided with the distribution.
.\" 3. All advertising materials mentioning features or use of this software
.\" must display the following acknowledgement:
.\" This product includes software developed by the University of
.\" California, Berkeley and its contributors.
.\" 4. Neither the name of the University nor the names of its contributors
.\" may be used to endorse or promote products derived from this software
.\" without specific prior written permission.
.\"
.\" THIS SOFTWARE IS PROVIDED BY THE REGENTS AND CONTRIBUTORS ``AS IS'' AND
.\" THIS SOFTWARE IS PROVIDED BY Berkeley Software Design, Inc. ``AS IS'' AND
.\" ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE
.\" IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE
.\" ARE DISCLAIMED. IN NO EVENT SHALL THE REGENTS OR CONTRIBUTORS BE LIABLE
.\" ARE DISCLAIMED. IN NO EVENT SHALL Berkeley Software Design, Inc. BE LIABLE
.\" FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL
.\" DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS
.\" OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION)
@ -29,10 +22,9 @@
.\" OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF
.\" SUCH DAMAGE.
.\"
.\" From: @(#)rcmd.3 8.1 (Berkeley) 6/4/93
.\" $FreeBSD$
.\"
.Dd May 21, 1998
.Dd "July 11, 1997"
.Dt IF_NAMETOINDEX 3
.Os
.Sh NAME
@ -40,103 +32,104 @@
.Nm if_indextoname ,
.Nm if_nameindex ,
.Nm if_freenameindex
.Nd convert interface index to name, and vice versa
.Sh LIBRARY
.Lb libc
.Nd provide mappings between interface names and indexes
.Sh SYNOPSIS
.In sys/types.h
.In sys/socket.h
.In net/if.h
.Ft "unsigned int"
.Ft unsigned int
.Fn if_nametoindex "const char *ifname"
.Ft "char *"
.Ft char *
.Fn if_indextoname "unsigned int ifindex" "char *ifname"
.Ft "struct if_nameindex *"
.Ft struct if_nameindex *
.Fn if_nameindex "void"
.Ft "void"
.Ft void
.Fn if_freenameindex "struct if_nameindex *ptr"
.Sh DESCRIPTION
The functions map interface index to readable interface name
(such as
.Dq Li lo0 ) ,
and vice versa.
.Pp
.Fn if_nametoindex
converts readable interface name to interface index
.Pp positive integer value .
If the specified interface does not exist, 0 will be returned.
.Pp
.Fn if_indextoname
converts interface index to readable interface name.
The
.Fa ifname
argument must point to a buffer of at least
.Dv IF_NAMESIZE
bytes into which the interface name corresponding to the specified index is
returned.
.Dv ( IF_NAMESIZE
is also defined in
.Aq Pa net/if.h
and its value includes a terminating null byte at the end of the
interface name.)
This pointer is also the return value of the function.
If there is no interface corresponding to the specified index,
.Dv NULL
is returned.
.Fn if_nametoindex
function maps the interface name specified in
.Ar ifname
to its corresponding index.
If the specified interface does not exist, it returns 0.
.Pp
The
.Fn if_indextoname
function maps the interface index specified in
.Ar ifindex
to it corresponding name, which is copied into the
buffer pointed to by
.Ar ifname ,
which must be of at least IFNAMSIZ bytes.
This pointer is also the return value of the function.
If there is no interface corresponding to the specified
index, NULL is returned.
.Pp
The
.Fn if_nameindex
returns an array of
.Fa if_nameindex
structures.
.Fa if_nametoindex
is also defined in
.Aq Pa net/if.h ,
and is as follows:
.Bd -literal -offset
struct if_nameindex {
function returns an array of
.Nm if_nameindex
structures, one structure per interface, as
defined in the include file
.Aq Pa net/if.h .
The
.Nm if_nameindex
structure contains at least the following entries:
.Bd -literal
unsigned int if_index; /* 1, 2, ... */
char *if_name; /* null terminated name: "le0", ... */
};
.Ed
.Pp
The end of the array of structures is indicated by a structure with
an
.Fa if_index
The end of the array of structures is indicated by a structure with an
.Nm if_index
of 0 and an
.Fa if_name
of
.Dv NULL .
The function returns a
.Dv NULL
pointer upon an error.
The memory used for this array of structures along with the interface
names pointed to by the
.Fa if_name
members is obtained dynamically.
This memory is freed by the
.Fn if_freenameindex
function.
.Nm if_name
of NULL.
A NULL pointer is returned upon an error.
.Pp
The
.Fn if_freenameindex
takes a pointer that was returned by
.Fn if_nameindex
as argument
.Pq Fa ptr ,
and it reclaims the region allocated.
.Sh DIAGNOSTICS
function frees the dynamic memory that was
allocated by
.Fn if_nameindex .
.Sh RETURN VALUES
Upon successful completion,
.Fn if_nametoindex
returns 0 on error, positive integer on success.
returns the index number of the interface.
If the interface is not found, a value of 0 is returned and
.Va errno
is set to
.Er ENXIO .
A value of 0 is also returned if an error
occurs while retrieving the list of interfaces via
.Xr getifaddrs 3 .
.Pp
Upon successful completion,
.Fn if_indextoname
and
returns
.Ar ifname .
If the interface is not found, a NULL pointer is returned and
.Va errno
is set to
.Er ENXIO .
A NULL pointer is also returned if an error
occurs while retrieving the list of interfaces via
.Xr getifaddrs 3 .
.Pp
The
.Fn if_nameindex
return
.Dv NULL
on errors.
returns a NULL pointer if an error
occurs while retrieving the list of interfaces via
.Xr getifaddrs 3 ,
or if sufficient memory cannot be allocated.
.Sh SEE ALSO
R. Gilligan, S. Thomson, J. Bound, and W. Stevens,
``Basic Socket Interface Extensions for IPv6,'' RFC2553, March 1999.
.Sh HISTORY
The implementation first appeared in WIDE Hydrangea IPv6 protocol stack kit.
.Xr getifaddrs 3 ,
.Xr networking 4
.Sh STANDARDS
These functions are defined in ``Basic Socket Interface Extensions for IPv6''
(RFC2533).
The
.Fn if_nametoindex ,
.Fn if_indextoname ,
.Fn if_nameindex ,
and
.Fn if_freenameindex
functions conform to RFC 2553.
.Sh HISTORY
The implementation first appeared in BSDI BSD/OS.

88
lib/libc/net/if_indextoname.c Normal file
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@ -0,0 +1,88 @@
/* $KAME: if_indextoname.c,v 1.7 2000/11/08 03:09:30 itojun Exp $ */
/*-
* Copyright (c) 1997, 2000
* Berkeley Software Design, Inc. All rights reserved.
*
* Redistribution and use in source and binary forms, with or without
* modification, are permitted provided that the following conditions
* are met:
* 1. Redistributions of source code must retain the above copyright
* notice, this list of conditions and the following disclaimer.
*
* THIS SOFTWARE IS PROVIDED BY Berkeley Software Design, Inc. ``AS IS'' AND
* ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE
* IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE
* ARE DISCLAIMED. IN NO EVENT SHALL Berkeley Software Design, Inc. BE LIABLE
* FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL
* DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS
* OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION)
* HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT
* LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY
* OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF
* SUCH DAMAGE.
*
* BSDI Id: if_indextoname.c,v 2.3 2000/04/17 22:38:05 dab Exp
*/
#include <sys/cdefs.h>
__FBSDID("$FreeBSD$");
#include <sys/types.h>
#include <sys/socket.h>
#include <net/if_dl.h>
#include <net/if.h>
#include <ifaddrs.h>
#include <stdlib.h>
#include <string.h>
#include <errno.h>
/*
* From RFC 2533:
*
* The second function maps an interface index into its corresponding
* name.
*
* #include <net/if.h>
*
* char *if_indextoname(unsigned int ifindex, char *ifname);
*
* The ifname argument must point to a buffer of at least IF_NAMESIZE
* bytes into which the interface name corresponding to the specified
* index is returned. (IF_NAMESIZE is also defined in <net/if.h> and
* its value includes a terminating null byte at the end of the
* interface name.) This pointer is also the return value of the
* function. If there is no interface corresponding to the specified
* index, NULL is returned, and errno is set to ENXIO, if there was a
* system error (such as running out of memory), if_indextoname returns
* NULL and errno would be set to the proper value (e.g., ENOMEM).
*/
char *
if_indextoname(unsigned int ifindex, char *ifname)
{
struct ifaddrs *ifaddrs, *ifa;
int error = 0;
if (getifaddrs(&ifaddrs) < 0)
return(NULL); /* getifaddrs properly set errno */
for (ifa = ifaddrs; ifa != NULL; ifa = ifa->ifa_next) {
if (ifa->ifa_addr &&
ifa->ifa_addr->sa_family == AF_LINK &&
ifindex == ((struct sockaddr_dl*)ifa->ifa_addr)->sdl_index)
break;
}
if (ifa == NULL) {
error = ENXIO;
ifname = NULL;
}
else
strncpy(ifname, ifa->ifa_name, IFNAMSIZ);
freeifaddrs(ifaddrs);
errno = error;
return(ifname);
}

147
lib/libc/net/if_nameindex.c Normal file
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@ -0,0 +1,147 @@
/* $KAME: if_nameindex.c,v 1.8 2000/11/24 08:20:01 itojun Exp $ */
/*-
* Copyright (c) 1997, 2000
* Berkeley Software Design, Inc. All rights reserved.
*
* Redistribution and use in source and binary forms, with or without
* modification, are permitted provided that the following conditions
* are met:
* 1. Redistributions of source code must retain the above copyright
* notice, this list of conditions and the following disclaimer.
*
* THIS SOFTWARE IS PROVIDED BY Berkeley Software Design, Inc. ``AS IS'' AND
* ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE
* IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE
* ARE DISCLAIMED. IN NO EVENT SHALL Berkeley Software Design, Inc. BE LIABLE
* FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL
* DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS
* OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION)
* HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT
* LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY
* OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF
* SUCH DAMAGE.
*
* BSDI Id: if_nameindex.c,v 2.3 2000/04/17 22:38:05 dab Exp
*/
#include <sys/cdefs.h>
__FBSDID("$FreeBSD$");
#include <sys/types.h>
#include <sys/socket.h>
#include <net/if_dl.h>
#include <net/if.h>
#include <ifaddrs.h>
#include <stdlib.h>
#include <string.h>
/*
* From RFC 2553:
*
* 4.3 Return All Interface Names and Indexes
*
* The if_nameindex structure holds the information about a single
* interface and is defined as a result of including the <net/if.h>
* header.
*
* struct if_nameindex {
* unsigned int if_index;
* char *if_name;
* };
*
* The final function returns an array of if_nameindex structures, one
* structure per interface.
*
* struct if_nameindex *if_nameindex(void);
*
* The end of the array of structures is indicated by a structure with
* an if_index of 0 and an if_name of NULL. The function returns a NULL
* pointer upon an error, and would set errno to the appropriate value.
*
* The memory used for this array of structures along with the interface
* names pointed to by the if_name members is obtained dynamically.
* This memory is freed by the next function.
*
* 4.4. Free Memory
*
* The following function frees the dynamic memory that was allocated by
* if_nameindex().
*
* #include <net/if.h>
*
* void if_freenameindex(struct if_nameindex *ptr);
*
* The argument to this function must be a pointer that was returned by
* if_nameindex().
*/
struct if_nameindex *
if_nameindex(void)
{
struct ifaddrs *ifaddrs, *ifa;
unsigned int ni;
int nbytes;
struct if_nameindex *ifni, *ifni2;
char *cp;
if (getifaddrs(&ifaddrs) < 0)
return(NULL);
/*
* First, find out how many interfaces there are, and how
* much space we need for the string names.
*/
ni = 0;
nbytes = 0;
for (ifa = ifaddrs; ifa != NULL; ifa = ifa->ifa_next) {
if (ifa->ifa_addr &&
ifa->ifa_addr->sa_family == AF_LINK) {
nbytes += strlen(ifa->ifa_name) + 1;
ni++;
}
}
/*
* Next, allocate a chunk of memory, use the first part
* for the array of structures, and the last part for
* the strings.
*/
cp = malloc((ni + 1) * sizeof(struct if_nameindex) + nbytes);
ifni = (struct if_nameindex *)cp;
if (ifni == NULL)
goto out;
cp += (ni + 1) * sizeof(struct if_nameindex);
/*
* Now just loop through the list of interfaces again,
* filling in the if_nameindex array and making copies
* of all the strings.
*/
ifni2 = ifni;
for (ifa = ifaddrs; ifa != NULL; ifa = ifa->ifa_next) {
if (ifa->ifa_addr &&
ifa->ifa_addr->sa_family == AF_LINK) {
ifni2->if_index =
((struct sockaddr_dl*)ifa->ifa_addr)->sdl_index;
ifni2->if_name = cp;
strcpy(cp, ifa->ifa_name);
ifni2++;
cp += strlen(cp) + 1;
}
}
/*
* Finally, don't forget to terminate the array.
*/
ifni2->if_index = 0;
ifni2->if_name = NULL;
out:
freeifaddrs(ifaddrs);
return(ifni);
}
void
if_freenameindex(struct if_nameindex *ptr)
{
free(ptr);
}

83
lib/libc/net/if_nametoindex.c Normal file
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@ -0,0 +1,83 @@
/* $KAME: if_nametoindex.c,v 1.6 2000/11/24 08:18:54 itojun Exp $ */
/*-
* Copyright (c) 1997, 2000
* Berkeley Software Design, Inc. All rights reserved.
*
* Redistribution and use in source and binary forms, with or without
* modification, are permitted provided that the following conditions
* are met:
* 1. Redistributions of source code must retain the above copyright
* notice, this list of conditions and the following disclaimer.
*
* THIS SOFTWARE IS PROVIDED BY Berkeley Software Design, Inc. ``AS IS'' AND
* ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE
* IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE
* ARE DISCLAIMED. IN NO EVENT SHALL Berkeley Software Design, Inc. BE LIABLE
* FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL
* DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS
* OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION)
* HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT
* LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY
* OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF
* SUCH DAMAGE.
*
* BSDI Id: if_nametoindex.c,v 2.3 2000/04/17 22:38:05 dab Exp
*/
#include <sys/cdefs.h>
__FBSDID("$FreeBSD$");
#include <sys/types.h>
#include <sys/socket.h>
#include <net/if.h>
#include <net/if_dl.h>
#include <ifaddrs.h>
#include <stdlib.h>
#include <string.h>
#include <errno.h>
/*
* From RFC 2553:
*
* 4.1 Name-to-Index
*
*
* The first function maps an interface name into its corresponding
* index.
*
* #include <net/if.h>
*
* unsigned int if_nametoindex(const char *ifname);
*
* If the specified interface name does not exist, the return value is
* 0, and errno is set to ENXIO. If there was a system error (such as
* running out of memory), the return value is 0 and errno is set to the
* proper value (e.g., ENOMEM).
*/
unsigned int
if_nametoindex(const char *ifname)
{
struct ifaddrs *ifaddrs, *ifa;
unsigned int ni;
if (getifaddrs(&ifaddrs) < 0)
return(0);
ni = 0;
for (ifa = ifaddrs; ifa != NULL; ifa = ifa->ifa_next) {
if (ifa->ifa_addr &&
ifa->ifa_addr->sa_family == AF_LINK &&
strcmp(ifa->ifa_name, ifname) == 0) {
ni = ((struct sockaddr_dl*)ifa->ifa_addr)->sdl_index;
break;
}
}
freeifaddrs(ifaddrs);
if (!ni)
errno = ENXIO;
return(ni);
}

236
lib/libc/net/ifname.c
View File

@ -1,236 +0,0 @@
/* $KAME: ifname.c,v 1.4 2001/08/20 02:32:40 itojun Exp $ */
/*
* Copyright (C) 1995, 1996, 1997, and 1998 WIDE Project.
* All rights reserved.
*
* Redistribution and use in source and binary forms, with or without
* modification, are permitted provided that the following conditions
* are met:
* 1. Redistributions of source code must retain the above copyright
* notice, this list of conditions and the following disclaimer.
* 2. Redistributions in binary form must reproduce the above copyright
* notice, this list of conditions and the following disclaimer in the
* documentation and/or other materials provided with the distribution.
* 3. Neither the name of the project nor the names of its contributors
* may be used to endorse or promote products derived from this software
* without specific prior written permission.
*
* THIS SOFTWARE IS PROVIDED BY THE PROJECT AND CONTRIBUTORS ``AS IS'' AND
* ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE
* IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE
* ARE DISCLAIMED. IN NO EVENT SHALL THE PROJECT OR CONTRIBUTORS BE LIABLE
* FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL
* DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS
* OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION)
* HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT
* LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY
* OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF
* SUCH DAMAGE.
*/
#include <sys/cdefs.h>
__FBSDID("$FreeBSD$");
/*
* TODO:
* - prototype defs into arpa/inet.h, not net/if.h (bsd-api-new-02)
*/
#include <sys/param.h>
#include <sys/socket.h>
#include <sys/sockio.h>
#include <sys/sysctl.h>
#include <net/if.h>
#include <net/route.h>
#include <net/if_dl.h>
#include <errno.h>
#include <stdlib.h>
#include <string.h>
#define ROUNDUP(a) \
((a) > 0 ? (1 + (((a) - 1) | (sizeof(long) - 1))) : sizeof(long))
#define ADVANCE(x, n) (x += ROUNDUP((n)->sa_len))
static unsigned int
if_onametoindex(ifname)
const char *ifname;
{
struct if_nameindex *iff = if_nameindex(), *ifx;
int ret;
if (iff == NULL) return 0;
ifx = iff;
while (ifx->if_name != NULL) {
if (strcmp(ifx->if_name, ifname) == 0) {
ret = ifx->if_index;
if_freenameindex(iff);
return ret;
}
ifx++;
}
if_freenameindex(iff);
errno = ENXIO;
return 0;
}
unsigned int
if_nametoindex(ifname)
const char *ifname;
{
int s;
struct ifreq ifr;
s = socket(AF_INET, SOCK_DGRAM, 0);
if (s == -1)
return (0);
strlcpy(ifr.ifr_name, ifname, sizeof(ifr.ifr_name));
if (ioctl(s, SIOCGIFINDEX, &ifr) == -1) {
close (s);
return (if_onametoindex(ifname));
}
close(s);
return (ifr.ifr_index);
}
char *
if_indextoname(ifindex, ifname)
unsigned int ifindex;
char *ifname; /* at least IF_NAMESIZE */
{
struct if_nameindex *iff = if_nameindex(), *ifx;
char *cp, *dp;
if (iff == NULL) return NULL;
ifx = iff;
while (ifx->if_index != 0) {
if (ifx->if_index == ifindex) {
cp = ifname;
dp = ifx->if_name;
while ((*cp++ = *dp++)) ;
if_freenameindex(iff);
return (ifname);
}
ifx++;
}
if_freenameindex(iff);
errno = ENXIO;
return NULL;
}
struct if_nameindex *
if_nameindex()
{
size_t needed;
int mib[6], i, ifn = 0, off = 0, hlen;
char *buf = NULL, *lim, *next, *cp, *ifbuf = NULL;
struct rt_msghdr *rtm;
struct if_msghdr *ifm;
struct sockaddr *sa;
struct sockaddr_dl *sdl;
struct if_nameindex *ret = NULL;
static int ifxs = 64; /* initial upper limit */
struct _ifx {
int if_index;
int if_off;
} *ifx = NULL;
mib[0] = CTL_NET;
mib[1] = PF_ROUTE;
mib[2] = 0; /* protocol */
mib[3] = 0; /* wildcard address family */
mib[4] = NET_RT_IFLIST;
mib[5] = 0; /* no flags */
if (sysctl(mib, 6, NULL, &needed, NULL, 0) < 0)
return NULL;
if ((buf = malloc(needed)) == NULL) {
errno = ENOMEM;
goto end;
}
/* XXX: we may have allocated too much than necessary */
if ((ifbuf = malloc(needed)) == NULL) {
errno = ENOMEM;
goto end;
}
if ((ifx = (struct _ifx *)malloc(sizeof(*ifx) * ifxs)) == NULL) {
errno = ENOMEM;
goto end;
}
if (sysctl(mib, 6, buf, &needed, NULL, 0) < 0) {
/* sysctl has set errno */
goto end;
}
lim = buf + needed;
for (next = buf; next < lim; next += rtm->rtm_msglen) {
rtm = (struct rt_msghdr *)next;
if (rtm->rtm_version != RTM_VERSION) {
errno = EPROTONOSUPPORT;
goto end;
}
switch (rtm->rtm_type) {
case RTM_IFINFO:
ifm = (struct if_msghdr *)rtm;
ifx[ifn].if_index = ifm->ifm_index;
ifx[ifn].if_off = off;
cp = (char *)(ifm + 1);
for (i = 1; i; i <<= 1) {
if (i & ifm->ifm_addrs) {
sa = (struct sockaddr *)cp;
if (i == RTA_IFP &&
sa->sa_family == AF_LINK) {
sdl = (struct sockaddr_dl *)sa;
memcpy(ifbuf + off,
sdl->sdl_data,
sdl->sdl_nlen);
off += sdl->sdl_nlen;
*(ifbuf + off) = '\0';
off++;
}
ADVANCE(cp, sa);
}
}
if (++ifn == ifxs) {
/* we need more memory */
struct _ifx *newifx;
ifxs *= 2;
if ((newifx = (struct _ifx *)malloc(sizeof(*newifx) * ifxs)) == NULL) {
errno = ENOMEM;
goto end;
}
/* copy and free old data */
memcpy(newifx, ifx, (sizeof(*ifx) * ifxs) / 2);
free(ifx);
ifx = newifx;
}
}
}
hlen = sizeof(struct if_nameindex) * (ifn + 1);
if ((cp = (char *)malloc(hlen + off)) == NULL) {
errno = ENOMEM;
goto end;
}
bcopy(ifbuf, cp + hlen, off);
ret = (struct if_nameindex *)cp;
for (i = 0; i < ifn; i++) {
ret[i].if_index = ifx[i].if_index;
ret[i].if_name = cp + hlen + ifx[i].if_off;
}
ret[ifn].if_index = 0;
ret[ifn].if_name = NULL;
end:
if (buf) free(buf);
if (ifbuf) free(ifbuf);
if (ifx) free(ifx);
return ret;
}
void if_freenameindex(ptr)
struct if_nameindex *ptr;
{
free(ptr);
}