interfaceiter.c revision 0c27b3fe77ac1d5094ba3521e8142d9e7973133f
/*
* Copyright (C) 1999-2001, 2004, 2007-2009, 2013-2016 Internet Systems Consortium, Inc. ("ISC")
*
* This Source Code Form is subject to the terms of the Mozilla Public
* License, v. 2.0. If a copy of the MPL was not distributed with this
* file, You can obtain one at http://mozilla.org/MPL/2.0/.
*/
/* $Id: interfaceiter.c,v 1.15 2009/01/18 23:48:14 tbox 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/print.h>
#include <isc/result.h>
#include <isc/string.h>
#include <isc/strerror.h>
#include <isc/types.h>
#include <isc/util.h>
void InitSockets(void);
/* Common utility functions */
/*
* Extract the network address part from a "struct sockaddr".
*
* The address family is given explicitly
* 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;
SOCKET socket;
INTERFACE_INFO IFData; /* Current Interface Info */
int numIF; /* Current Interface count */
int v4IF; /* Number of IPv4 Interfaces */
INTERFACE_INFO *buf4; /* Buffer for WSAIoctl data. */
unsigned int buf4size; /* Bytes allocated. */
INTERFACE_INFO *pos4; /* Current offset in IF List */
SOCKET_ADDRESS_LIST *buf6;
unsigned int buf6size; /* Bytes allocated. */
unsigned int pos6;
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:
memmove(&dst->type.in,
&((struct sockaddr_in *) src)->sin_addr,
sizeof(struct in_addr));
break;
case AF_INET6:
memmove(&dst->type.in6,
&((struct sockaddr_in6 *) src)->sin6_addr,
sizeof(struct in6_addr));
dst->zone = ((struct sockaddr_in6 *) src)->sin6_scope_id;
break;
default:
INSIST(0);
break;
}
}
isc_result_t
isc_interfaceiter_create(isc_mem_t *mctx, isc_interfaceiter_t **iterp) {
char strbuf[ISC_STRERRORSIZE];
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);
InitSockets();
iter->mctx = mctx;
iter->buf4 = NULL;
iter->buf6 = NULL;
iter->pos4 = NULL;
iter->pos6 = 0;
iter->buf6size = 0;
iter->buf4size = 0;
iter->result = ISC_R_FAILURE;
iter->numIF = 0;
iter->v4IF = 0;
/*
* Create an unbound datagram socket to do the
* SIO_GET_INTERFACE_LIST WSAIoctl on.
*/
iter->socket = socket(AF_INET, SOCK_DGRAM, 0);
if (iter->socket == INVALID_SOCKET) {
error = WSAGetLastError();
if (error == WSAEAFNOSUPPORT)
goto inet6_only;
isc__strerror(error, strbuf, sizeof(strbuf));
UNEXPECTED_ERROR(__FILE__, __LINE__,
"making interface scan socket: %s",
strbuf);
result = ISC_R_UNEXPECTED;
goto socket_failure;
}
/*
* Get the interface configuration, allocating more memory if
* necessary.
*/
iter->buf4size = IFCONF_SIZE_INITIAL*sizeof(INTERFACE_INFO);
for (;;) {
iter->buf4 = isc_mem_get(mctx, iter->buf4size);
if (iter->buf4 == NULL) {
result = ISC_R_NOMEMORY;
goto alloc_failure;
}
if (WSAIoctl(iter->socket, SIO_GET_INTERFACE_LIST,
0, 0, iter->buf4, iter->buf4size,
&bytesReturned, 0, 0) == SOCKET_ERROR)
{
error = WSAGetLastError();
if (error != WSAEFAULT && error != WSAENOBUFS) {
errno = error;
isc__strerror(error, strbuf, sizeof(strbuf));
UNEXPECTED_ERROR(__FILE__, __LINE__,
"get interface configuration: %s",
strbuf);
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->buf4size))
break;
}
if (iter->buf4size >= 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->buf4, iter->buf4size);
iter->buf4size += IFCONF_SIZE_INCREMENT *
sizeof(INTERFACE_INFO);
}
/*
* A newly created iterator has an undefined position
* until isc_interfaceiter_first() is called.
*/
iter->v4IF = bytesReturned/sizeof(INTERFACE_INFO);
/* We don't need the socket any more, so close it */
closesocket(iter->socket);
inet6_only:
/*
* Create an unbound datagram socket to do the
* SIO_ADDRESS_LIST_QUERY WSAIoctl on.
*/
iter->socket = socket(AF_INET6, SOCK_DGRAM, 0);
if (iter->socket == INVALID_SOCKET) {
error = WSAGetLastError();
if (error == WSAEAFNOSUPPORT)
goto inet_only;
isc__strerror(error, strbuf, sizeof(strbuf));
UNEXPECTED_ERROR(__FILE__, __LINE__,
"making interface scan socket: %s",
strbuf);
result = ISC_R_UNEXPECTED;
goto ioctl_failure;
}
/*
* Get the interface configuration, allocating more memory if
* necessary.
*/
iter->buf6size = sizeof(SOCKET_ADDRESS_LIST) +
IFCONF_SIZE_INITIAL*sizeof(SOCKET_ADDRESS);
for (;;) {
iter->buf6 = isc_mem_get(mctx, iter->buf6size);
if (iter->buf6 == NULL) {
result = ISC_R_NOMEMORY;
goto ioctl_failure;
}
if (WSAIoctl(iter->socket, SIO_ADDRESS_LIST_QUERY,
0, 0, iter->buf6, iter->buf6size,
&bytesReturned, 0, 0) == SOCKET_ERROR)
{
error = WSAGetLastError();
if (error != WSAEFAULT && error != WSAENOBUFS) {
errno = error;
isc__strerror(error, strbuf, sizeof(strbuf));
UNEXPECTED_ERROR(__FILE__, __LINE__,
"sio address list query: %s",
strbuf);
result = ISC_R_UNEXPECTED;
goto ioctl6_failure;
}
/*
* EINVAL. Retry with a bigger buffer.
*/
} else
break;
if (iter->buf6size >= IFCONF_SIZE_MAX*sizeof(SOCKET_ADDRESS)) {
UNEXPECTED_ERROR(__FILE__, __LINE__,
"get interface configuration: "
"maximum buffer size exceeded");
result = ISC_R_UNEXPECTED;
goto ioctl6_failure;
}
isc_mem_put(mctx, iter->buf6, iter->buf6size);
iter->buf6size += IFCONF_SIZE_INCREMENT *
sizeof(SOCKET_ADDRESS);
}
closesocket(iter->socket);
inet_only:
iter->magic = IFITER_MAGIC;
*iterp = iter;
return (ISC_R_SUCCESS);
ioctl6_failure:
isc_mem_put(mctx, iter->buf6, iter->buf6size);
ioctl_failure:
if (iter->buf4 != NULL)
isc_mem_put(mctx, iter->buf4, iter->buf4size);
alloc_failure:
if (iter->socket != INVALID_SOCKET)
(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) {
BOOL ifNamed = FALSE;
unsigned long flags;
REQUIRE(VALID_IFITER(iter));
REQUIRE(iter->numIF >= 0);
memset(&iter->current, 0, sizeof(iter->current));
iter->current.af = AF_INET;
get_addr(AF_INET, &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(AF_INET, &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.
*/
get_addr(AF_INET, &iter->current.netmask,
(struct sockaddr *)&(iter->IFData.iiNetmask));
return (ISC_R_SUCCESS);
}
static isc_result_t
internal_current6(isc_interfaceiter_t *iter) {
BOOL ifNamed = FALSE;
int i;
REQUIRE(VALID_IFITER(iter));
REQUIRE(iter->pos6 >= 0);
REQUIRE(iter->buf6 != 0);
memset(&iter->current, 0, sizeof(iter->current));
iter->current.af = AF_INET6;
get_addr(AF_INET6, &iter->current.address,
iter->buf6->Address[iter->pos6].lpSockaddr);
/*
* Get interface flags.
*/
iter->current.flags = INTERFACE_F_UP;
if (ifNamed == FALSE)
sprintf(iter->current.name,
"TCP/IPv6 Interface %d", iter->pos6 + 1);
for (i = 0; i< 16; i++)
iter->current.netmask.type.in6.s6_addr[i] = 0xff;
iter->current.netmask.family = AF_INET6;
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->v4IF)
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->pos4 = (INTERFACE_INFO *)(iter->buf4 + (iter->v4IF));
iter->pos4--;
if (&(iter->pos4) < &(iter->buf4))
return (ISC_R_NOMORE);
memset(&(iter->IFData), 0, sizeof(INTERFACE_INFO));
memmove(&(iter->IFData), iter->pos4, sizeof(INTERFACE_INFO));
iter->numIF++;
return (ISC_R_SUCCESS);
}
static isc_result_t
internal_next6(isc_interfaceiter_t *iter) {
if (iter->pos6 == 0)
return (ISC_R_NOMORE);
iter->pos6--;
return (ISC_R_SUCCESS);
}
isc_result_t
isc_interfaceiter_current(isc_interfaceiter_t *iter,
isc_interface_t *ifdata) {
REQUIRE(iter->result == ISC_R_SUCCESS);
memmove(ifdata, &iter->current, sizeof(*ifdata));
return (ISC_R_SUCCESS);
}
isc_result_t
isc_interfaceiter_first(isc_interfaceiter_t *iter) {
REQUIRE(VALID_IFITER(iter));
if (iter->buf6 != NULL)
iter->pos6 = iter->buf6->iAddressCount;
iter->result = ISC_R_SUCCESS;
return (isc_interfaceiter_next(iter));
}
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_NOMORE) {
result = internal_next6(iter);
if (result != ISC_R_SUCCESS)
break;
result = internal_current6(iter);
if (result != ISC_R_IGNORE)
break;
} else if (result != ISC_R_SUCCESS)
break;
result = internal_current(iter);
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));
if (iter->buf4 != NULL)
isc_mem_put(iter->mctx, iter->buf4, iter->buf4size);
if (iter->buf6 != NULL)
isc_mem_put(iter->mctx, iter->buf6, iter->buf6size);
iter->magic = 0;
isc_mem_put(iter->mctx, iter, sizeof(*iter));
*iterp = NULL;
}