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/*
* Copyright (C) Internet Systems Consortium, Inc. ("ISC")
*
* Permission to use, copy, modify, and/or distribute this software for any
* purpose with or without fee is hereby granted, provided that the above
* copyright notice and this permission notice appear in all copies.
*
* THE SOFTWARE IS PROVIDED "AS IS" AND ISC DISCLAIMS ALL WARRANTIES WITH
* REGARD TO THIS SOFTWARE INCLUDING ALL IMPLIED WARRANTIES OF MERCHANTABILITY
* AND FITNESS. IN NO EVENT SHALL ISC BE LIABLE FOR ANY SPECIAL, DIRECT,
* INDIRECT, OR CONSEQUENTIAL DAMAGES OR ANY DAMAGES WHATSOEVER RESULTING FROM
* LOSS OF USE, DATA OR PROFITS, WHETHER IN AN ACTION OF CONTRACT, NEGLIGENCE
* OR OTHER TORTIOUS ACTION, ARISING OUT OF OR IN CONNECTION WITH THE USE OR
* PERFORMANCE OF THIS SOFTWARE.
*/
/* $Id: ifiter_sysctl.c,v 1.5 2020/01/09 13:47:14 florian Exp $ */
/*! \file
* \brief
* Obtain the list of network interfaces using sysctl.
* See TCP/IP Illustrated Volume 2, sections 19.8, 19.14,
* and 19.16.
*/
#include <sys/param.h>
#include <sys/sysctl.h>
#include <net/route.h>
#include <net/if_dl.h>
/* XXX what about Alpha? */
#ifdef sgi
#define ROUNDUP(a) ((a) > 0 ? \
(1 + (((a) - 1) | (sizeof(__uint64_t) - 1))) : \
sizeof(__uint64_t))
#else
#define ROUNDUP(a) ((a) > 0 ? (1 + (((a) - 1) | (sizeof(long) - 1))) \
: sizeof(long))
#endif
#define IFITER_MAGIC ISC_MAGIC('I', 'F', 'I', 'S')
#define VALID_IFITER(t) ISC_MAGIC_VALID(t, IFITER_MAGIC)
struct isc_interfaceiter {
unsigned int magic; /* Magic number. */
isc_mem_t *mctx;
void *buf; /* Buffer for sysctl data. */
unsigned int bufsize; /* Bytes allocated. */
unsigned int bufused; /* Bytes used. */
unsigned int pos; /* Current offset in
sysctl data. */
isc_interface_t current; /* Current interface data. */
isc_result_t result; /* Last result code. */
};
static int mib[6] = {
CTL_NET,
PF_ROUTE,
0,
0, /* Any address family. */
NET_RT_IFLIST,
0 /* Flags. */
};
isc_result_t
isc_interfaceiter_create(isc_mem_t *mctx, isc_interfaceiter_t **iterp) {
isc_interfaceiter_t *iter;
isc_result_t result;
size_t bufsize;
size_t bufused;
char strbuf[ISC_STRERRORSIZE];
REQUIRE(mctx != NULL);
REQUIRE(iterp != NULL);
REQUIRE(*iterp == NULL);
iter = isc_mem_get(mctx, sizeof(*iter));
if (iter == NULL)
return (ISC_R_NOMEMORY);
iter->mctx = mctx;
iter->buf = 0;
/*
* Determine the amount of memory needed.
*/
bufsize = 0;
if (sysctl(mib, 6, NULL, &bufsize, NULL, (size_t) 0) < 0) {
isc__strerror(errno, strbuf, sizeof(strbuf));
UNEXPECTED_ERROR(__FILE__, __LINE__,
isc_msgcat_get(isc_msgcat,
ISC_MSGSET_IFITERSYSCTL,
ISC_MSG_GETIFLISTSIZE,
"getting interface "
"list size: sysctl: %s"),
strbuf);
result = ISC_R_UNEXPECTED;
goto failure;
}
iter->bufsize = bufsize;
iter->buf = isc_mem_get(iter->mctx, iter->bufsize);
if (iter->buf == NULL) {
result = ISC_R_NOMEMORY;
goto failure;
}
bufused = bufsize;
if (sysctl(mib, 6, iter->buf, &bufused, NULL, (size_t) 0) < 0) {
isc__strerror(errno, strbuf, sizeof(strbuf));
UNEXPECTED_ERROR(__FILE__, __LINE__,
isc_msgcat_get(isc_msgcat,
ISC_MSGSET_IFITERSYSCTL,
ISC_MSG_GETIFLIST,
"getting interface list: "
"sysctl: %s"),
strbuf);
result = ISC_R_UNEXPECTED;
goto failure;
}
iter->bufused = bufused;
INSIST(iter->bufused <= iter->bufsize);
/*
* A newly created iterator has an undefined position
* until isc_interfaceiter_first() is called.
*/
iter->pos = (unsigned int) -1;
iter->result = ISC_R_FAILURE;
iter->magic = IFITER_MAGIC;
*iterp = iter;
return (ISC_R_SUCCESS);
failure:
if (iter->buf != NULL)
isc_mem_put(mctx, iter->buf, iter->bufsize);
isc_mem_put(mctx, iter, sizeof(*iter));
return (result);
}
/*
* Get information about the current interface to iter->current.
* If successful, return ISC_R_SUCCESS.
* If the interface has an unsupported address family,
* return ISC_R_IGNORE. In case of other failure,
* return ISC_R_UNEXPECTED.
*/
static isc_result_t
internal_current(isc_interfaceiter_t *iter) {
struct ifa_msghdr *ifam, *ifam_end;
REQUIRE(VALID_IFITER(iter));
REQUIRE (iter->pos < (unsigned int) iter->bufused);
ifam = (struct ifa_msghdr *) ((char *) iter->buf + iter->pos);
ifam_end = (struct ifa_msghdr *) ((char *) iter->buf + iter->bufused);
if (ifam->ifam_type == RTM_IFINFO) {
struct if_msghdr *ifm = (struct if_msghdr *) ifam;
struct sockaddr_dl *sdl = (struct sockaddr_dl *) (ifm + 1);
unsigned int namelen;
memset(&iter->current, 0, sizeof(iter->current));
namelen = sdl->sdl_nlen;
if (namelen > sizeof(iter->current.name) - 1)
namelen = sizeof(iter->current.name) - 1;
memset(iter->current.name, 0, sizeof(iter->current.name));
memmove(iter->current.name, sdl->sdl_data, namelen);
iter->current.flags = 0;
if ((ifam->ifam_flags & IFF_UP) != 0)
iter->current.flags |= INTERFACE_F_UP;
if ((ifam->ifam_flags & IFF_POINTOPOINT) != 0)
iter->current.flags |= INTERFACE_F_POINTTOPOINT;
if ((ifam->ifam_flags & IFF_LOOPBACK) != 0)
iter->current.flags |= INTERFACE_F_LOOPBACK;
/*
* This is not an interface address.
* Force another iteration.
*/
return (ISC_R_IGNORE);
} else if (ifam->ifam_type == RTM_NEWADDR) {
int i;
int family;
struct sockaddr *mask_sa = NULL;
struct sockaddr *addr_sa = NULL;
struct sockaddr *dst_sa = NULL;
struct sockaddr *sa = (struct sockaddr *)(ifam + 1);
family = sa->sa_family;
for (i = 0; i < RTAX_MAX; i++)
{
if ((ifam->ifam_addrs & (1 << i)) == 0)
continue;
INSIST(sa < (struct sockaddr *) ifam_end);
switch (i) {
case RTAX_NETMASK: /* Netmask */
mask_sa = sa;
break;
case RTAX_IFA: /* Interface address */
addr_sa = sa;
break;
case RTAX_BRD: /* Broadcast or destination address */
dst_sa = sa;
break;
}
sa = (struct sockaddr *)((char*)(sa)
+ ROUNDUP(sa->sa_len));
}
if (addr_sa == NULL)
return (ISC_R_IGNORE);
family = addr_sa->sa_family;
if (family != AF_INET && family != AF_INET6)
return (ISC_R_IGNORE);
iter->current.af = family;
get_addr(family, &iter->current.address, addr_sa,
iter->current.name);
if (mask_sa != NULL)
get_addr(family, &iter->current.netmask, mask_sa,
iter->current.name);
if (dst_sa != NULL &&
(iter->current.flags & INTERFACE_F_POINTTOPOINT) != 0)
get_addr(family, &iter->current.dstaddress, dst_sa,
iter->current.name);
return (ISC_R_SUCCESS);
} else {
printf(isc_msgcat_get(isc_msgcat, ISC_MSGSET_IFITERSYSCTL,
ISC_MSG_UNEXPECTEDTYPE,
"warning: unexpected interface list "
"message type\n"));
return (ISC_R_IGNORE);
}
}
/*
* Step the iterator to the next interface. Unlike
* isc_interfaceiter_next(), this may leave the iterator
* positioned on an interface that will ultimately
* be ignored. Return ISC_R_NOMORE if there are no more
* interfaces, otherwise ISC_R_SUCCESS.
*/
static isc_result_t
internal_next(isc_interfaceiter_t *iter) {
struct ifa_msghdr *ifam;
REQUIRE (iter->pos < (unsigned int) iter->bufused);
ifam = (struct ifa_msghdr *) ((char *) iter->buf + iter->pos);
iter->pos += ifam->ifam_msglen;
if (iter->pos >= iter->bufused)
return (ISC_R_NOMORE);
return (ISC_R_SUCCESS);
}
static void
internal_destroy(isc_interfaceiter_t *iter) {
UNUSED(iter); /* Unused. */
/*
* Do nothing.
*/
}
static
void internal_first(isc_interfaceiter_t *iter) {
iter->pos = 0;
}
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