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freebsd/lib/libc/net/getifmaddrs.c
Bruce M Simpson 2554d76f85 Add the userland part of the NET_RT_IFMALIST sysctl MIB. A new function,
getifmaddrs(), is added to retrieve current multicast group memberships.

Reviewed by:	harti
2003-11-14 18:53:22 +00:00

208 lines
5.2 KiB
C

/*
* Copyright (c) 2003 Bruce M. Simpson.
* 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 Bruce M. Simpson.
* 4. Neither the name of Bruce M. Simpson nor the names of other
* contributors may be used to endorse or promote products derived
* from this software without specific prior written permission.
*
* THIS SOFTWARE IS PROVIDED BY BRUCE M. SIMPSON AND AFFILIATES
* ``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 BRUCE M. SIMPSON 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("$FreeBSD$");
#include "namespace.h"
#include <sys/param.h>
#include <sys/sysctl.h>
#include <sys/ioctl.h>
#include <sys/socket.h>
#include <net/if.h>
#include <net/if_dl.h>
#include <net/route.h>
#include <errno.h>
#include <ifaddrs.h>
#include <stdlib.h>
#include <string.h>
#include "un-namespace.h"
#define SALIGN (sizeof(long) - 1)
#define SA_RLEN(sa) ((sa)->sa_len ? (((sa)->sa_len + SALIGN) & ~SALIGN) : \
(SALIGN + 1))
#define MAX_SYSCTL_TRY 5
#define RTA_MASKS (RTA_GATEWAY | RTA_IFP | RTA_IFA)
int
getifmaddrs(struct ifmaddrs **pif)
{
int icnt = 1;
int dcnt = 0;
int ntry = 0;
u_short idx = 0;
size_t len;
size_t needed;
int mib[6];
int i;
char *buf;
char *data;
char *names;
char *next;
char *p;
struct ifma_msghdr *ifmam;
struct ifmaddrs *ifa, *ift;
struct rt_msghdr *rtm;
struct sockaddr *sa;
mib[0] = CTL_NET;
mib[1] = PF_ROUTE;
mib[2] = 0; /* protocol */
mib[3] = 0; /* wildcard address family */
mib[4] = NET_RT_IFMALIST;
mib[5] = 0; /* no flags */
do {
if (sysctl(mib, 6, NULL, &needed, NULL, 0) < 0)
return (-1);
if ((buf = malloc(needed)) == NULL)
return (-1);
if (sysctl(mib, 6, buf, &needed, NULL, 0) < 0) {
if (errno != ENOMEM || ++ntry >= MAX_SYSCTL_TRY) {
free(buf);
return (-1);
}
free(buf);
buf = NULL;
}
} while (buf == NULL);
for (next = buf; next < buf + needed; next += rtm->rtm_msglen) {
rtm = (struct rt_msghdr *)(void *)next;
if (rtm->rtm_version != RTM_VERSION)
continue;
switch (rtm->rtm_type) {
case RTM_NEWMADDR:
ifmam = (struct ifma_msghdr *)(void *)rtm;
if ((ifmam->ifmam_addrs & RTA_IFA) == 0)
break;
icnt++;
p = (char *)(ifmam + 1);
for (i = 0; i < RTAX_MAX; i++) {
if ((RTA_MASKS & ifmam->ifmam_addrs &
(1 << i)) == 0)
continue;
sa = (struct sockaddr *)(void *)p;
len = SA_RLEN(sa);
dcnt += len;
p += len;
}
break;
}
}
data = malloc(sizeof(struct ifmaddrs) * icnt + dcnt);
if (data == NULL) {
free(buf);
return (-1);
}
ifa = (struct ifmaddrs *)(void *)data;
data += sizeof(struct ifmaddrs) * icnt;
names = data + dcnt;
memset(ifa, 0, sizeof(struct ifmaddrs) * icnt);
ift = ifa;
idx = 0;
for (next = buf; next < buf + needed; next += rtm->rtm_msglen) {
rtm = (struct rt_msghdr *)(void *)next;
if (rtm->rtm_version != RTM_VERSION)
continue;
switch (rtm->rtm_type) {
case RTM_NEWMADDR:
ifmam = (struct ifma_msghdr *)(void *)rtm;
if ((ifmam->ifmam_addrs & RTA_IFA) == 0)
break;
p = (char *)(ifmam + 1);
for (i = 0; i < RTAX_MAX; i++) {
if ((RTA_MASKS & ifmam->ifmam_addrs &
(1 << i)) == 0)
continue;
sa = (struct sockaddr *)(void *)p;
len = SA_RLEN(sa);
switch (i) {
case RTAX_GATEWAY:
ift->ifma_lladdr =
(struct sockaddr *)(void *)data;
memcpy(data, p, len);
data += len;
break;
case RTAX_IFP:
ift->ifma_name =
(struct sockaddr *)(void *)data;
memcpy(data, p, len);
data += len;
break;
case RTAX_IFA:
ift->ifma_addr =
(struct sockaddr *)(void *)data;
memcpy(data, p, len);
data += len;
break;
default:
data += len;
break;
}
p += len;
}
ift->ifma_next = ift + 1;
ift = ift->ifma_next;
break;
}
}
free(buf);
if (ift > ifa) {
ift--;
ift->ifma_next = NULL;
*pif = ifa;
} else {
*pif = NULL;
free(ifa);
}
return (0);
}
void
freeifmaddrs(struct ifmaddrs *ifmp)
{
free(ifmp);
}