Commit 3d8c1213 authored by Danny Mayer's avatar Danny Mayer
Browse files

Interface Iteration routines

parent fc4bae7e
/*
* Copyright (C) 1999, 2000 Internet Software Consortium.
*
* Permission to use, copy, modify, and 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 INTERNET SOFTWARE CONSORTIUM
* DISCLAIMS ALL WARRANTIES WITH REGARD TO THIS SOFTWARE INCLUDING ALL
* IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS. IN NO EVENT SHALL
* INTERNET SOFTWARE CONSORTIUM 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: interfaceiter.c,v 1.1 2001/07/06 05:25:20 mayer Exp $ */
/*
* Note that this code will need to be revisited to support IPv6 Interfaces.
* For now we just iterate through IPv4 interfaces.
*/
#include <config.h>
#include <winsock2.h>
#include <ws2tcpip.h>
#include <sys/types.h>
#include <stdio.h>
#include <stdlib.h>
#include <errno.h>
#include <isc/interfaceiter.h>
#include <isc/mem.h>
#include <isc/result.h>
#include <isc/string.h>
#include <isc/types.h>
#include <isc/util.h>
#include "errno2result.h"
/* Common utility functions */
/*
* Extract the network address part from a "struct sockaddr".
*
* The address family is given explicity
* instead of using src->sa_family, because the latter does not work
* for copying a network mask obtained by SIOCGIFNETMASK (it does
* not have a valid address family).
*/
#define IFITER_MAGIC 0x49464954U /* IFIT. */
#define VALID_IFITER(t) ((t) != NULL && (t)->magic == IFITER_MAGIC)
struct isc_interfaceiter {
unsigned int magic; /* Magic number. */
isc_mem_t *mctx;
int socket;
INTERFACE_INFO IFData; /* Current Interface Info */
int numIF; /* Current Interface count */
int totalIF; /* Total Number of Interfaces */
INTERFACE_INFO *buf; /* Buffer for WSAIoctl data. */
unsigned int bufsize; /* Bytes allocated. */
INTERFACE_INFO *pos; /* Current offset in IF List */
isc_interface_t current; /* Current interface data. */
isc_result_t result; /* Last result code. */
};
/*
* Size of buffer for SIO_GET_INTERFACE_LIST, in number of interfaces.
* We assume no sane system will have more than than 1K of IP addresses on
* all of its adapters.
*/
#define IFCONF_SIZE_INITIAL 16
#define IFCONF_SIZE_INCREMENT 64
#define IFCONF_SIZE_MAX 1040
static void
get_addr(unsigned int family, isc_netaddr_t *dst, struct sockaddr *src) {
dst->family = family;
switch (family) {
case AF_INET:
memcpy(&dst->type.in,
&((struct sockaddr_in *) src)->sin_addr,
sizeof(struct in_addr));
break;
case AF_INET6:
memcpy(&dst->type.in6,
&((struct sockaddr_in6 *) src)->sin6_addr,
sizeof(struct in6_addr));
break;
default:
INSIST(0);
break;
}
}
isc_result_t
isc_interfaceiter_create(isc_mem_t *mctx, isc_interfaceiter_t **iterp) {
isc_interfaceiter_t *iter;
isc_result_t result;
int error;
unsigned long bytesReturned = 0;
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 = NULL;
/*
* Create an unbound datagram socket to do the SIO_GET_INTERFACE_LIST WSAIoctl on.
*/
if ((iter->socket = socket(AF_INET, SOCK_DGRAM, 0)) < 0) {
UNEXPECTED_ERROR(__FILE__, __LINE__,
"making interface scan socket: %s",
strerror(errno));
result = ISC_R_UNEXPECTED;
goto socket_failure;
}
/*
* Get the interface configuration, allocating more memory if
* necessary.
*/
iter->bufsize = IFCONF_SIZE_INITIAL*sizeof(INTERFACE_INFO);
for (;;) {
iter->buf = isc_mem_get(mctx, iter->bufsize);
if (iter->buf == NULL) {
result = ISC_R_NOMEMORY;
goto alloc_failure;
}
if (WSAIoctl(iter->socket, SIO_GET_INTERFACE_LIST, 0, 0, iter->buf, iter->bufsize,
&bytesReturned, 0, 0)
== SOCKET_ERROR) {
error = WSAGetLastError();
if (error != WSAEFAULT && error != WSAENOBUFS) {
errno = error;
UNEXPECTED_ERROR(__FILE__, __LINE__,
"get interface configuration: %s",
NTstrerror(error));
result = ISC_R_UNEXPECTED;
goto ioctl_failure;
}
/*
* EINVAL. Retry with a bigger buffer.
*/
} else {
/*
* The WSAIoctl succeeded.
* If the number of the returned bytes is the same as the buffer size,
* we will grow it just in case and retry.
*/
if (bytesReturned > 0 && (bytesReturned < iter->bufsize))
break;
}
if (iter->bufsize >= IFCONF_SIZE_MAX*sizeof(INTERFACE_INFO)) {
UNEXPECTED_ERROR(__FILE__, __LINE__,
"get interface configuration: "
"maximum buffer size exceeded");
result = ISC_R_UNEXPECTED;
goto ioctl_failure;
}
isc_mem_put(mctx, iter->buf, iter->bufsize);
iter->bufsize += IFCONF_SIZE_INCREMENT*sizeof(INTERFACE_INFO);
}
/*
* A newly created iterator has an undefined position
* until isc_interfaceiter_first() is called.
*/
iter->pos = NULL;
iter->result = ISC_R_FAILURE;
iter->numIF = 0;
iter->totalIF = bytesReturned/sizeof(INTERFACE_INFO);
iter->magic = IFITER_MAGIC;
*iterp = iter;
/* We don't need the socket any more, so close it */
closesocket(iter->socket);
return (ISC_R_SUCCESS);
ioctl_failure:
isc_mem_put(mctx, iter->buf, iter->bufsize);
alloc_failure:
(void) closesocket(iter->socket);
socket_failure:
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, or if
* some operation on it fails, return ISC_R_IGNORE to make
* the higher-level iterator code ignore it.
*/
static isc_result_t
internal_current(isc_interfaceiter_t *iter, int family) {
BOOL ifNamed = FALSE;
unsigned long flags;
REQUIRE(VALID_IFITER(iter));
REQUIRE(iter->numIF >= 0);
memset(&iter->current, 0, sizeof(iter->current));
iter->current.af = family;
get_addr(family, &iter->current.address,
(struct sockaddr *)&(iter->IFData.iiAddress));
/*
* Get interface flags.
*/
iter->current.flags = 0;
flags = iter->IFData.iiFlags;
if ((flags & IFF_UP) != 0)
iter->current.flags |= INTERFACE_F_UP;
if ((flags & IFF_POINTTOPOINT) != 0)
{
iter->current.flags |= INTERFACE_F_POINTTOPOINT;
sprintf(iter->current.name, "PPP Interface %d", iter->numIF);
ifNamed = TRUE;
}
if ((flags & IFF_LOOPBACK) != 0)
{
iter->current.flags |= INTERFACE_F_LOOPBACK;
sprintf(iter->current.name, "Loopback Interface %d", iter->numIF);
ifNamed = TRUE;
}
/*
* If the interface is point-to-point, get the destination address.
*/
if ((iter->current.flags & INTERFACE_F_POINTTOPOINT) != 0) {
get_addr(family, &iter->current.dstaddress,
(struct sockaddr *)&(iter->IFData.iiBroadcastAddress));
}
if(ifNamed == FALSE)
sprintf(iter->current.name, "TCP/IP Interface %d", iter->numIF);
/*
* Get the network mask.
*/
switch (family) {
case AF_INET:
/*
* Ignore the HP/UX warning about "interger overflow during
* conversion. It comes from its own macro definition,
* and is really hard to shut up.
*/
get_addr(family, &iter->current.netmask,
(struct sockaddr *)&(iter->IFData.iiNetmask));
break;
case AF_INET6: {
break;
}
}
return (ISC_R_SUCCESS);
}
/*
* 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) {
if (iter->numIF >= iter->totalIF)
return (ISC_R_NOMORE);
/*
* The first one needs to be set up to point to the last
* Element of the array. Go to the end and back up
* Microsoft's implementation is peculiar for returning
* the list in reverse order
*/
if(iter->numIF == 0)
{
iter->pos = (INTERFACE_INFO *)(iter->buf + (iter->totalIF));
}
iter->pos--;
if(&(iter->pos) < &(iter->buf))
return (ISC_R_NOMORE);
memset(&(iter->IFData), 0, sizeof(INTERFACE_INFO));
memcpy(&(iter->IFData), iter->pos, sizeof(INTERFACE_INFO));
iter->numIF++;
return (ISC_R_SUCCESS);
}
/*
* The remaining code is common to the sysctl and ioctl case.
*/
isc_result_t
isc_interfaceiter_current(isc_interfaceiter_t *iter,
isc_interface_t *ifdata)
{
REQUIRE(iter->result == ISC_R_SUCCESS);
memcpy(ifdata, &iter->current, sizeof(*ifdata));
return (ISC_R_SUCCESS);
}
isc_result_t
isc_interfaceiter_first(isc_interfaceiter_t *iter) {
isc_result_t result;
REQUIRE(VALID_IFITER(iter));
iter->numIF = 0;
for (;;) {
result = internal_next(iter);
if (result != ISC_R_SUCCESS)
break;
result = internal_current(iter, AF_INET);
if (result != ISC_R_IGNORE)
break;
}
iter->result = result;
return (result);
}
isc_result_t
isc_interfaceiter_next(isc_interfaceiter_t *iter) {
isc_result_t result;
REQUIRE(VALID_IFITER(iter));
REQUIRE(iter->result == ISC_R_SUCCESS);
for (;;) {
result = internal_next(iter);
if (result != ISC_R_SUCCESS)
break;
result = internal_current(iter,AF_INET);
if (result != ISC_R_IGNORE)
break;
}
iter->result = result;
return (result);
}
void
isc_interfaceiter_destroy(isc_interfaceiter_t **iterp)
{
isc_interfaceiter_t *iter;
REQUIRE(iterp != NULL);
iter = *iterp;
REQUIRE(VALID_IFITER(iter));
isc_mem_put(iter->mctx, iter->buf, iter->bufsize);
iter->magic = 0;
isc_mem_put(iter->mctx, iter, sizeof *iter);
*iterp = NULL;
}
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