nexmon – Rev 1
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/* -*- Mode: c; tab-width: 8; indent-tabs-mode: 1; c-basic-offset: 8; -*- */
/*
* Copyright (c) 1994, 1995, 1996, 1997, 1998
* The Regents of the University of California. 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 Computer Systems
* Engineering Group at Lawrence Berkeley Laboratory.
* 4. Neither the name of the University nor of the Laboratory 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
* 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
* 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.
*/
#ifdef HAVE_CONFIG_H
#include "config.h"
#endif
#ifdef WIN32
#include <pcap-stdinc.h>
#else /* WIN32 */
#include <sys/param.h>
#ifndef MSDOS
#include <sys/file.h>
#endif
#include <sys/ioctl.h>
#include <sys/socket.h>
#ifdef HAVE_SYS_SOCKIO_H
#include <sys/sockio.h>
#endif
struct mbuf; /* Squelch compiler warnings on some platforms for */
struct rtentry; /* declarations in <net/if.h> */
#include <net/if.h>
#include <netinet/in.h>
#endif /* WIN32 */
#include <ctype.h>
#include <errno.h>
#include <memory.h>
#include <stdio.h>
#include <stdlib.h>
#include <string.h>
#if !defined(WIN32) && !defined(__BORLANDC__)
#include <unistd.h>
#endif /* !WIN32 && !__BORLANDC__ */
#ifdef HAVE_LIMITS_H
#include <limits.h>
#else
#define INT_MAX 2147483647
#endif
#include "pcap-int.h"
#ifdef HAVE_OS_PROTO_H
#include "os-proto.h"
#endif
/* Not all systems have IFF_LOOPBACK */
#ifdef IFF_LOOPBACK
#define ISLOOPBACK(name, flags) ((flags) & IFF_LOOPBACK)
#else
#define ISLOOPBACK(name, flags) ((name)[0] == 'l' && (name)[1] == 'o' && \
(isdigit((unsigned char)((name)[2])) || (name)[2] == '\0'))
#endif
#ifdef IFF_UP
#define ISUP(flags) ((flags) & IFF_UP)
#else
#define ISUP(flags) 0
#endif
#ifdef IFF_RUNNING
#define ISRUNNING(flags) ((flags) & IFF_RUNNING)
#else
#define ISRUNNING(flags) 0
#endif
struct sockaddr *
dup_sockaddr(struct sockaddr *sa, size_t sa_length)
{
struct sockaddr *newsa;
if ((newsa = malloc(sa_length)) == NULL)
return (NULL);
return (memcpy(newsa, sa, sa_length));
}
/*
* Construct a "figure of merit" for an interface, for use when sorting
* the list of interfaces, in which interfaces that are up are superior
* to interfaces that aren't up, interfaces that are up and running are
* superior to interfaces that are up but not running, and non-loopback
* interfaces that are up and running are superior to loopback interfaces,
* and interfaces with the same flags have a figure of merit that's higher
* the lower the instance number.
*
* The goal is to try to put the interfaces most likely to be useful for
* capture at the beginning of the list.
*
* The figure of merit, which is lower the "better" the interface is,
* has the uppermost bit set if the interface isn't running, the bit
* below that set if the interface isn't up, the bit below that set
* if the interface is a loopback interface, and the interface index
* in the 29 bits below that. (Yes, we assume u_int is 32 bits.)
*/
static u_int
get_figure_of_merit(pcap_if_t *dev)
{
const char *cp;
u_int n;
if (strcmp(dev->name, "any") == 0) {
/*
* Give the "any" device an artificially high instance
* number, so it shows up after all other non-loopback
* interfaces.
*/
n = 0x1FFFFFFF; /* 29 all-1 bits */
} else {
/*
* A number at the end of the device name string is
* assumed to be a unit number.
*/
cp = dev->name + strlen(dev->name) - 1;
while (cp-1 >= dev->name && *(cp-1) >= '0' && *(cp-1) <= '9')
cp--;
if (*cp >= '0' && *cp <= '9')
n = atoi(cp);
else
n = 0;
}
if (!(dev->flags & PCAP_IF_RUNNING))
n |= 0x80000000;
if (!(dev->flags & PCAP_IF_UP))
n |= 0x40000000;
if (dev->flags & PCAP_IF_LOOPBACK)
n |= 0x20000000;
return (n);
}
/*
* Look for a given device in the specified list of devices.
*
* If we find it, return 0 and set *curdev_ret to point to it.
*
* If we don't find it, check whether we can open it:
*
* If that fails with PCAP_ERROR_NO_SUCH_DEVICE or
* PCAP_ERROR_IFACE_NOT_UP, don't attempt to add an entry for
* it, as that probably means it exists but doesn't support
* packet capture.
*
* Otherwise, attempt to add an entry for it, with the specified
* ifnet flags and description, and, if that succeeds, return 0
* and set *curdev_ret to point to the new entry, otherwise
* return PCAP_ERROR and set errbuf to an error message.
*/
int
add_or_find_if(pcap_if_t **curdev_ret, pcap_if_t **alldevs, const char *name,
u_int flags, const char *description, char *errbuf)
{
pcap_t *p;
pcap_if_t *curdev, *prevdev, *nextdev;
u_int this_figure_of_merit, nextdev_figure_of_merit;
char open_errbuf[PCAP_ERRBUF_SIZE];
int ret;
/*
* Is there already an entry in the list for this interface?
*/
for (curdev = *alldevs; curdev != NULL; curdev = curdev->next) {
if (strcmp(name, curdev->name) == 0)
break; /* yes, we found it */
}
if (curdev == NULL) {
/*
* No, we didn't find it.
*
* Can we open this interface for live capture?
*
* We do this check so that interfaces that are
* supplied by the interface enumeration mechanism
* we're using but that don't support packet capture
* aren't included in the list. Loopback interfaces
* on Solaris are an example of this; we don't just
* omit loopback interfaces on all platforms because
* you *can* capture on loopback interfaces on some
* OSes.
*
* On OS X, we don't do this check if the device
* name begins with "wlt"; at least some versions
* of OS X offer monitor mode capturing by having
* a separate "monitor mode" device for each wireless
* adapter, rather than by implementing the ioctls
* that {Free,Net,Open,DragonFly}BSD provide.
* Opening that device puts the adapter into monitor
* mode, which, at least for some adapters, causes
* them to deassociate from the network with which
* they're associated.
*
* Instead, we try to open the corresponding "en"
* device (so that we don't end up with, for users
* without sufficient privilege to open capture
* devices, a list of adapters that only includes
* the wlt devices).
*/
#ifdef __APPLE__
if (strncmp(name, "wlt", 3) == 0) {
char *en_name;
size_t en_name_len;
/*
* Try to allocate a buffer for the "en"
* device's name.
*/
en_name_len = strlen(name) - 1;
en_name = malloc(en_name_len + 1);
if (en_name == NULL) {
(void)snprintf(errbuf, PCAP_ERRBUF_SIZE,
"malloc: %s", pcap_strerror(errno));
return (-1);
}
strcpy(en_name, "en");
strcat(en_name, name + 3);
p = pcap_create(en_name, open_errbuf);
free(en_name);
} else
#endif /* __APPLE */
p = pcap_create(name, open_errbuf);
if (p == NULL) {
/*
* The attempt to create the pcap_t failed;
* that's probably an indication that we're
* out of memory.
*
* Don't bother including this interface,
* but don't treat it as an error.
*/
*curdev_ret = NULL;
return (0);
}
/* Small snaplen, so we don't try to allocate much memory. */
pcap_set_snaplen(p, 68);
ret = pcap_activate(p);
pcap_close(p);
switch (ret) {
case PCAP_ERROR_NO_SUCH_DEVICE:
case PCAP_ERROR_IFACE_NOT_UP:
/*
* We expect these two errors - they're the
* reason we try to open the device.
*
* PCAP_ERROR_NO_SUCH_DEVICE typically means
* "there's no such device *known to the
* OS's capture mechanism*", so, even though
* it might be a valid network interface, you
* can't capture on it (e.g., the loopback
* device in Solaris up to Solaris 10, or
* the vmnet devices in OS X with VMware
* Fusion). We don't include those devices
* in our list of devices, as there's no
* point in doing so - they're not available
* for capture.
*
* PCAP_ERROR_IFACE_NOT_UP means that the
* OS's capture mechanism doesn't work on
* interfaces not marked as up; some capture
* mechanisms *do* support that, so we no
* longer reject those interfaces out of hand,
* but we *do* want to reject them if they
* can't be opened for capture.
*/
*curdev_ret = NULL;
return (0);
}
/*
* Yes, we can open it, or we can't, for some other
* reason.
*
* If we can open it, we want to offer it for
* capture, as you can capture on it. If we can't,
* we want to offer it for capture, so that, if
* the user tries to capture on it, they'll get
* an error and they'll know why they can't
* capture on it (e.g., insufficient permissions)
* or they'll report it as a problem (and then
* have the error message to provide as information).
*
* Allocate a new entry.
*/
curdev = malloc(sizeof(pcap_if_t));
if (curdev == NULL) {
(void)snprintf(errbuf, PCAP_ERRBUF_SIZE,
"malloc: %s", pcap_strerror(errno));
return (-1);
}
/*
* Fill in the entry.
*/
curdev->next = NULL;
curdev->name = strdup(name);
if (curdev->name == NULL) {
(void)snprintf(errbuf, PCAP_ERRBUF_SIZE,
"malloc: %s", pcap_strerror(errno));
free(curdev);
return (-1);
}
if (description != NULL) {
/*
* We have a description for this interface.
*/
curdev->description = strdup(description);
if (curdev->description == NULL) {
(void)snprintf(errbuf, PCAP_ERRBUF_SIZE,
"malloc: %s", pcap_strerror(errno));
free(curdev->name);
free(curdev);
return (-1);
}
} else {
/*
* We don't.
*/
curdev->description = NULL;
}
curdev->addresses = NULL; /* list starts out as empty */
curdev->flags = 0;
if (ISLOOPBACK(name, flags))
curdev->flags |= PCAP_IF_LOOPBACK;
if (ISUP(flags))
curdev->flags |= PCAP_IF_UP;
if (ISRUNNING(flags))
curdev->flags |= PCAP_IF_RUNNING;
/*
* Add it to the list, in the appropriate location.
* First, get the "figure of merit" for this
* interface.
*/
this_figure_of_merit = get_figure_of_merit(curdev);
/*
* Now look for the last interface with an figure of merit
* less than or equal to the new interface's figure of
* merit.
*
* We start with "prevdev" being NULL, meaning we're before
* the first element in the list.
*/
prevdev = NULL;
for (;;) {
/*
* Get the interface after this one.
*/
if (prevdev == NULL) {
/*
* The next element is the first element.
*/
nextdev = *alldevs;
} else
nextdev = prevdev->next;
/*
* Are we at the end of the list?
*/
if (nextdev == NULL) {
/*
* Yes - we have to put the new entry
* after "prevdev".
*/
break;
}
/*
* Is the new interface's figure of merit less
* than the next interface's figure of merit,
* meaning that the new interface is better
* than the next interface?
*/
nextdev_figure_of_merit = get_figure_of_merit(nextdev);
if (this_figure_of_merit < nextdev_figure_of_merit) {
/*
* Yes - we should put the new entry
* before "nextdev", i.e. after "prevdev".
*/
break;
}
prevdev = nextdev;
}
/*
* Insert before "nextdev".
*/
curdev->next = nextdev;
/*
* Insert after "prevdev" - unless "prevdev" is null,
* in which case this is the first interface.
*/
if (prevdev == NULL) {
/*
* This is the first interface. Pass back a
* pointer to it, and put "curdev" before
* "nextdev".
*/
*alldevs = curdev;
} else
prevdev->next = curdev;
}
*curdev_ret = curdev;
return (0);
}
/*
* Try to get a description for a given device.
* Returns a mallocated description if it could and NULL if it couldn't.
*
* XXX - on FreeBSDs that support it, should it get the sysctl named
* "dev.{adapter family name}.{adapter unit}.%desc" to get a description
* of the adapter? Note that "dev.an.0.%desc" is "Aironet PC4500/PC4800"
* with my Cisco 350 card, so the name isn't entirely descriptive. The
* "dev.an.0.%pnpinfo" has a better description, although one might argue
* that the problem is really a driver bug - if it can find out that it's
* a Cisco 340 or 350, rather than an old Aironet card, it should use
* that in the description.
*
* Do NetBSD, DragonflyBSD, or OpenBSD support this as well? FreeBSD
* and OpenBSD let you get a description, but it's not generated by the OS,
* it's set with another ioctl that ifconfig supports; we use that to get
* a description in FreeBSD and OpenBSD, but if there is no such
* description available, it still might be nice to get some description
* string based on the device type or something such as that.
*
* In OS X, the System Configuration framework can apparently return
* names in 10.4 and later.
*
* It also appears that freedesktop.org's HAL offers an "info.product"
* string, but the HAL specification says it "should not be used in any
* UI" and "subsystem/capability specific properties" should be used
* instead and, in any case, I think HAL is being deprecated in
* favor of other stuff such as DeviceKit. DeviceKit doesn't appear
* to have any obvious product information for devices, but maybe
* I haven't looked hard enough.
*
* Using the System Configuration framework, or HAL, or DeviceKit, or
* whatever, would require that libpcap applications be linked with
* the frameworks/libraries in question. That shouldn't be a problem
* for programs linking with the shared version of libpcap (unless
* you're running on AIX - which I think is the only UN*X that doesn't
* support linking a shared library with other libraries on which it
* depends, and having an executable linked only with the first shared
* library automatically pick up the other libraries when started -
* and using HAL or whatever). Programs linked with the static
* version of libpcap would have to use pcap-config with the --static
* flag in order to get the right linker flags in order to pick up
* the additional libraries/frameworks; those programs need that anyway
* for libpcap 1.1 and beyond on Linux, as, by default, it requires
* -lnl.
*
* Do any other UN*Xes, or desktop environments support getting a
* description?
*/
static char *
get_if_description(const char *name)
{
#ifdef SIOCGIFDESCR
char *description = NULL;
int s;
struct ifreq ifrdesc;
#ifndef IFDESCRSIZE
size_t descrlen = 64;
#else
size_t descrlen = IFDESCRSIZE;
#endif /* IFDESCRSIZE */
/*
* Get the description for the interface.
*/
memset(&ifrdesc, 0, sizeof ifrdesc);
strlcpy(ifrdesc.ifr_name, name, sizeof ifrdesc.ifr_name);
s = socket(AF_INET, SOCK_DGRAM, 0);
if (s >= 0) {
#ifdef __FreeBSD__
/*
* On FreeBSD, if the buffer isn't big enough for the
* description, the ioctl succeeds, but the description
* isn't copied, ifr_buffer.length is set to the description
* length, and ifr_buffer.buffer is set to NULL.
*/
for (;;) {
free(description);
if ((description = malloc(descrlen)) != NULL) {
ifrdesc.ifr_buffer.buffer = description;
ifrdesc.ifr_buffer.length = descrlen;
if (ioctl(s, SIOCGIFDESCR, &ifrdesc) == 0) {
if (ifrdesc.ifr_buffer.buffer ==
description)
break;
else
descrlen = ifrdesc.ifr_buffer.length;
} else {
/*
* Failed to get interface description.
*/
free(description);
description = NULL;
break;
}
} else
break;
}
#else /* __FreeBSD__ */
/*
* The only other OS that currently supports
* SIOCGIFDESCR is OpenBSD, and it has no way
* to get the description length - it's clamped
* to a maximum of IFDESCRSIZE.
*/
if ((description = malloc(descrlen)) != NULL) {
ifrdesc.ifr_data = (caddr_t)description;
if (ioctl(s, SIOCGIFDESCR, &ifrdesc) != 0) {
/*
* Failed to get interface description.
*/
free(description);
description = NULL;
}
}
#endif /* __FreeBSD__ */
close(s);
if (description != NULL && strlen(description) == 0) {
free(description);
description = NULL;
}
}
return (description);
#else /* SIOCGIFDESCR */
return (NULL);
#endif /* SIOCGIFDESCR */
}
/*
* Try to get a description for a given device, and then look for that
* device in the specified list of devices.
*
* If we find it, then, if the specified address isn't null, add it to
* the list of addresses for the device and return 0.
*
* If we don't find it, check whether we can open it:
*
* If that fails with PCAP_ERROR_NO_SUCH_DEVICE or
* PCAP_ERROR_IFACE_NOT_UP, don't attempt to add an entry for
* it, as that probably means it exists but doesn't support
* packet capture.
*
* Otherwise, attempt to add an entry for it, with the specified
* ifnet flags and description, and, if that succeeds, add the
* specified address to its list of addresses if that address is
* non-null, set *curdev_ret to point to the new entry, and
* return 0, otherwise return PCAP_ERROR and set errbuf to an
* error message.
*
* (We can get called with a null address because we might get a list
* of interface name/address combinations from the underlying OS, with
* the address being absent in some cases, rather than a list of
* interfaces with each interface having a list of addresses, so this
* call may be the only call made to add to the list, and we want to
* add interfaces even if they have no addresses.)
*/
int
add_addr_to_iflist(pcap_if_t **alldevs, const char *name, u_int flags,
struct sockaddr *addr, size_t addr_size,
struct sockaddr *netmask, size_t netmask_size,
struct sockaddr *broadaddr, size_t broadaddr_size,
struct sockaddr *dstaddr, size_t dstaddr_size,
char *errbuf)
{
char *description;
pcap_if_t *curdev;
description = get_if_description(name);
if (add_or_find_if(&curdev, alldevs, name, flags, description,
errbuf) == -1) {
free(description);
/*
* Error - give up.
*/
return (-1);
}
free(description);
if (curdev == NULL) {
/*
* Device wasn't added because it can't be opened.
* Not a fatal error.
*/
return (0);
}
if (addr == NULL) {
/*
* There's no address to add; this entry just meant
* "here's a new interface".
*/
return (0);
}
/*
* "curdev" is an entry for this interface, and we have an
* address for it; add an entry for that address to the
* interface's list of addresses.
*
* Allocate the new entry and fill it in.
*/
return (add_addr_to_dev(curdev, addr, addr_size, netmask,
netmask_size, broadaddr, broadaddr_size, dstaddr,
dstaddr_size, errbuf));
}
/*
* Add an entry to the list of addresses for an interface.
* "curdev" is the entry for that interface.
* If this is the first IP address added to the interface, move it
* in the list as appropriate.
*/
int
add_addr_to_dev(pcap_if_t *curdev,
struct sockaddr *addr, size_t addr_size,
struct sockaddr *netmask, size_t netmask_size,
struct sockaddr *broadaddr, size_t broadaddr_size,
struct sockaddr *dstaddr, size_t dstaddr_size,
char *errbuf)
{
pcap_addr_t *curaddr, *prevaddr, *nextaddr;
curaddr = malloc(sizeof(pcap_addr_t));
if (curaddr == NULL) {
(void)snprintf(errbuf, PCAP_ERRBUF_SIZE,
"malloc: %s", pcap_strerror(errno));
return (-1);
}
curaddr->next = NULL;
if (addr != NULL) {
curaddr->addr = dup_sockaddr(addr, addr_size);
if (curaddr->addr == NULL) {
(void)snprintf(errbuf, PCAP_ERRBUF_SIZE,
"malloc: %s", pcap_strerror(errno));
free(curaddr);
return (-1);
}
} else
curaddr->addr = NULL;
if (netmask != NULL) {
curaddr->netmask = dup_sockaddr(netmask, netmask_size);
if (curaddr->netmask == NULL) {
(void)snprintf(errbuf, PCAP_ERRBUF_SIZE,
"malloc: %s", pcap_strerror(errno));
if (curaddr->addr != NULL)
free(curaddr->addr);
free(curaddr);
return (-1);
}
} else
curaddr->netmask = NULL;
if (broadaddr != NULL) {
curaddr->broadaddr = dup_sockaddr(broadaddr, broadaddr_size);
if (curaddr->broadaddr == NULL) {
(void)snprintf(errbuf, PCAP_ERRBUF_SIZE,
"malloc: %s", pcap_strerror(errno));
if (curaddr->netmask != NULL)
free(curaddr->netmask);
if (curaddr->addr != NULL)
free(curaddr->addr);
free(curaddr);
return (-1);
}
} else
curaddr->broadaddr = NULL;
if (dstaddr != NULL) {
curaddr->dstaddr = dup_sockaddr(dstaddr, dstaddr_size);
if (curaddr->dstaddr == NULL) {
(void)snprintf(errbuf, PCAP_ERRBUF_SIZE,
"malloc: %s", pcap_strerror(errno));
if (curaddr->broadaddr != NULL)
free(curaddr->broadaddr);
if (curaddr->netmask != NULL)
free(curaddr->netmask);
if (curaddr->addr != NULL)
free(curaddr->addr);
free(curaddr);
return (-1);
}
} else
curaddr->dstaddr = NULL;
/*
* Find the end of the list of addresses.
*/
for (prevaddr = curdev->addresses; prevaddr != NULL; prevaddr = nextaddr) {
nextaddr = prevaddr->next;
if (nextaddr == NULL) {
/*
* This is the end of the list.
*/
break;
}
}
if (prevaddr == NULL) {
/*
* The list was empty; this is the first member.
*/
curdev->addresses = curaddr;
} else {
/*
* "prevaddr" is the last member of the list; append
* this member to it.
*/
prevaddr->next = curaddr;
}
return (0);
}
/*
* Look for a given device in the specified list of devices.
*
* If we find it, return 0.
*
* If we don't find it, check whether we can open it:
*
* If that fails with PCAP_ERROR_NO_SUCH_DEVICE or
* PCAP_ERROR_IFACE_NOT_UP, don't attempt to add an entry for
* it, as that probably means it exists but doesn't support
* packet capture.
*
* Otherwise, attempt to add an entry for it, with the specified
* ifnet flags and description, and, if that succeeds, return 0
* and set *curdev_ret to point to the new entry, otherwise
* return PCAP_ERROR and set errbuf to an error message.
*/
int
pcap_add_if(pcap_if_t **devlist, const char *name, u_int flags,
const char *description, char *errbuf)
{
pcap_if_t *curdev;
return (add_or_find_if(&curdev, devlist, name, flags, description,
errbuf));
}
/*
* Free a list of interfaces.
*/
void
pcap_freealldevs(pcap_if_t *alldevs)
{
pcap_if_t *curdev, *nextdev;
pcap_addr_t *curaddr, *nextaddr;
for (curdev = alldevs; curdev != NULL; curdev = nextdev) {
nextdev = curdev->next;
/*
* Free all addresses.
*/
for (curaddr = curdev->addresses; curaddr != NULL; curaddr = nextaddr) {
nextaddr = curaddr->next;
if (curaddr->addr)
free(curaddr->addr);
if (curaddr->netmask)
free(curaddr->netmask);
if (curaddr->broadaddr)
free(curaddr->broadaddr);
if (curaddr->dstaddr)
free(curaddr->dstaddr);
free(curaddr);
}
/*
* Free the name string.
*/
free(curdev->name);
/*
* Free the description string, if any.
*/
if (curdev->description != NULL)
free(curdev->description);
/*
* Free the interface.
*/
free(curdev);
}
}
#if !defined(WIN32) && !defined(MSDOS)
/*
* Return the name of a network interface attached to the system, or NULL
* if none can be found. The interface must be configured up; the
* lowest unit number is preferred; loopback is ignored.
*/
char *
pcap_lookupdev(errbuf)
register char *errbuf;
{
pcap_if_t *alldevs;
/* for old BSD systems, including bsdi3 */
#ifndef IF_NAMESIZE
#define IF_NAMESIZE IFNAMSIZ
#endif
static char device[IF_NAMESIZE + 1];
char *ret;
if (pcap_findalldevs(&alldevs, errbuf) == -1)
return (NULL);
if (alldevs == NULL || (alldevs->flags & PCAP_IF_LOOPBACK)) {
/*
* There are no devices on the list, or the first device
* on the list is a loopback device, which means there
* are no non-loopback devices on the list. This means
* we can't return any device.
*
* XXX - why not return a loopback device? If we can't
* capture on it, it won't be on the list, and if it's
* on the list, there aren't any non-loopback devices,
* so why not just supply it as the default device?
*/
(void)strlcpy(errbuf, "no suitable device found",
PCAP_ERRBUF_SIZE);
ret = NULL;
} else {
/*
* Return the name of the first device on the list.
*/
(void)strlcpy(device, alldevs->name, sizeof(device));
ret = device;
}
pcap_freealldevs(alldevs);
return (ret);
}
int
pcap_lookupnet(device, netp, maskp, errbuf)
register const char *device;
register bpf_u_int32 *netp, *maskp;
register char *errbuf;
{
register int fd;
register struct sockaddr_in *sin4;
struct ifreq ifr;
/*
* The pseudo-device "any" listens on all interfaces and therefore
* has the network address and -mask "0.0.0.0" therefore catching
* all traffic. Using NULL for the interface is the same as "any".
*/
if (!device || strcmp(device, "any") == 0
#ifdef HAVE_DAG_API
|| strstr(device, "dag") != NULL
#endif
#ifdef HAVE_SEPTEL_API
|| strstr(device, "septel") != NULL
#endif
#ifdef PCAP_SUPPORT_BT
|| strstr(device, "bluetooth") != NULL
#endif
#ifdef PCAP_SUPPORT_USB
|| strstr(device, "usbmon") != NULL
#endif
#ifdef HAVE_SNF_API
|| strstr(device, "snf") != NULL
#endif
) {
*netp = *maskp = 0;
return 0;
}
fd = socket(AF_INET, SOCK_DGRAM, 0);
if (fd < 0) {
(void)snprintf(errbuf, PCAP_ERRBUF_SIZE, "socket: %s",
pcap_strerror(errno));
return (-1);
}
memset(&ifr, 0, sizeof(ifr));
#ifdef linux
/* XXX Work around Linux kernel bug */
ifr.ifr_addr.sa_family = AF_INET;
#endif
(void)strlcpy(ifr.ifr_name, device, sizeof(ifr.ifr_name));
if (ioctl(fd, SIOCGIFADDR, (char *)&ifr) < 0) {
if (errno == EADDRNOTAVAIL) {
(void)snprintf(errbuf, PCAP_ERRBUF_SIZE,
"%s: no IPv4 address assigned", device);
} else {
(void)snprintf(errbuf, PCAP_ERRBUF_SIZE,
"SIOCGIFADDR: %s: %s",
device, pcap_strerror(errno));
}
(void)close(fd);
return (-1);
}
sin4 = (struct sockaddr_in *)&ifr.ifr_addr;
*netp = sin4->sin_addr.s_addr;
memset(&ifr, 0, sizeof(ifr));
#ifdef linux
/* XXX Work around Linux kernel bug */
ifr.ifr_addr.sa_family = AF_INET;
#endif
(void)strlcpy(ifr.ifr_name, device, sizeof(ifr.ifr_name));
if (ioctl(fd, SIOCGIFNETMASK, (char *)&ifr) < 0) {
(void)snprintf(errbuf, PCAP_ERRBUF_SIZE,
"SIOCGIFNETMASK: %s: %s", device, pcap_strerror(errno));
(void)close(fd);
return (-1);
}
(void)close(fd);
*maskp = sin4->sin_addr.s_addr;
if (*maskp == 0) {
if (IN_CLASSA(*netp))
*maskp = IN_CLASSA_NET;
else if (IN_CLASSB(*netp))
*maskp = IN_CLASSB_NET;
else if (IN_CLASSC(*netp))
*maskp = IN_CLASSC_NET;
else {
(void)snprintf(errbuf, PCAP_ERRBUF_SIZE,
"inet class for 0x%x unknown", *netp);
return (-1);
}
}
*netp &= *maskp;
return (0);
}
#elif defined(WIN32)
/*
* Return the name of a network interface attached to the system, or NULL
* if none can be found. The interface must be configured up; the
* lowest unit number is preferred; loopback is ignored.
*/
char *
pcap_lookupdev(errbuf)
register char *errbuf;
{
DWORD dwVersion;
DWORD dwWindowsMajorVersion;
dwVersion = GetVersion(); /* get the OS version */
dwWindowsMajorVersion = (DWORD)(LOBYTE(LOWORD(dwVersion)));
if (dwVersion >= 0x80000000 && dwWindowsMajorVersion >= 4) {
/*
* Windows 95, 98, ME.
*/
ULONG NameLength = 8192;
static char AdaptersName[8192];
if (PacketGetAdapterNames(AdaptersName,&NameLength) )
return (AdaptersName);
else
return NULL;
} else {
/*
* Windows NT (NT 4.0, W2K, WXP). Convert the names to UNICODE for backward compatibility
*/
ULONG NameLength = 8192;
static WCHAR AdaptersName[8192];
char *tAstr;
WCHAR *tUstr;
WCHAR *TAdaptersName = (WCHAR*)malloc(8192 * sizeof(WCHAR));
int NAdapts = 0;
if(TAdaptersName == NULL)
{
(void)snprintf(errbuf, PCAP_ERRBUF_SIZE, "memory allocation failure");
return NULL;
}
if ( !PacketGetAdapterNames((PTSTR)TAdaptersName,&NameLength) )
{
(void)snprintf(errbuf, PCAP_ERRBUF_SIZE,
"PacketGetAdapterNames: %s",
pcap_win32strerror());
free(TAdaptersName);
return NULL;
}
tAstr = (char*)TAdaptersName;
tUstr = (WCHAR*)AdaptersName;
/*
* Convert and copy the device names
*/
while(sscanf(tAstr, "%S", tUstr) > 0)
{
tAstr += strlen(tAstr) + 1;
tUstr += wcslen(tUstr) + 1;
NAdapts ++;
}
tAstr++;
*tUstr = 0;
tUstr++;
/*
* Copy the descriptions
*/
while(NAdapts--)
{
char* tmp = (char*)tUstr;
strcpy(tmp, tAstr);
tmp += strlen(tAstr) + 1;
tUstr = (WCHAR*)tmp;
tAstr += strlen(tAstr) + 1;
}
free(TAdaptersName);
return (char *)(AdaptersName);
}
}
int
pcap_lookupnet(device, netp, maskp, errbuf)
register const char *device;
register bpf_u_int32 *netp, *maskp;
register char *errbuf;
{
/*
* We need only the first IPv4 address, so we must scan the array returned by PacketGetNetInfo()
* in order to skip non IPv4 (i.e. IPv6 addresses)
*/
npf_if_addr if_addrs[MAX_NETWORK_ADDRESSES];
LONG if_addr_size = 1;
struct sockaddr_in *t_addr;
unsigned int i;
if (!PacketGetNetInfoEx((void *)device, if_addrs, &if_addr_size)) {
*netp = *maskp = 0;
return (0);
}
for(i=0; i<MAX_NETWORK_ADDRESSES; i++)
{
if(if_addrs[i].IPAddress.ss_family == AF_INET)
{
t_addr = (struct sockaddr_in *) &(if_addrs[i].IPAddress);
*netp = t_addr->sin_addr.S_un.S_addr;
t_addr = (struct sockaddr_in *) &(if_addrs[i].SubnetMask);
*maskp = t_addr->sin_addr.S_un.S_addr;
*netp &= *maskp;
return (0);
}
}
*netp = *maskp = 0;
return (0);
}
#endif /* !WIN32 && !MSDOS */