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libpcap/inet.c

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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.
*/
#ifndef lint
static const char rcsid[] _U_ =
"@(#) $Header: /tcpdump/master/libpcap/inet.c,v 1.75 2007-06-11 10:04:25 guy Exp $ (LBL)";
#endif
#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
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));
}
static int
get_instance(const char *name)
{
const char *cp, *endcp;
int n;
if (strcmp(name, "any") == 0) {
/*
* Give the "any" device an artificially high instance
* number, so it shows up after all other non-loopback
* interfaces.
*/
return INT_MAX;
}
endcp = name + strlen(name);
for (cp = name; cp < endcp && !isdigit((unsigned char)*cp); ++cp)
continue;
if (isdigit((unsigned char)*cp))
n = atoi(cp);
else
n = 0;
return (n);
}
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;
int this_instance;
/*
* 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_open_live(en_name, 68, 0, 0, errbuf);
free(en_name);
} else
#endif /* __APPLE */
p = pcap_open_live(name, 68, 0, 0, errbuf);
if (p == NULL) {
/*
* No. Don't bother including it.
* Don't treat this as an error, though.
*/
*curdev_ret = NULL;
return (0);
}
pcap_close(p);
/*
* Yes, we can open it.
* 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;
/*
* Add it to the list, in the appropriate location.
* First, get the instance number of this interface.
*/
this_instance = get_instance(name);
/*
* Now look for the last interface with an instance number
* less than or equal to the new interface's instance
* number - except that non-loopback interfaces are
* arbitrarily treated as having interface numbers less
* than those of loopback interfaces, so the loopback
* interfaces are put at the end of the list.
*
* 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 a non-loopback interface
* and the next interface a loopback interface?
*/
if (!(curdev->flags & PCAP_IF_LOOPBACK) &&
(nextdev->flags & PCAP_IF_LOOPBACK)) {
/*
* Yes, we should put the new entry
* before "nextdev", i.e. after "prevdev".
*/
break;
}
/*
* Is the new interface's instance number less
* than the next interface's instance number,
* and is it the case that the new interface is a
* non-loopback interface or the next interface is
* a loopback interface?
*
* (The goal of both loopback tests is to make
* sure that we never put a loopback interface
* before any non-loopback interface and that we
* always put a non-loopback interface before all
* loopback interfaces.)
*/
if (this_instance < get_instance(nextdev->name) &&
(!(curdev->flags & PCAP_IF_LOOPBACK) ||
(nextdev->flags & PCAP_IF_LOOPBACK))) {
/*
* 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);
}
/*
* 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?
* Do any other UN*Xes support getting a description?
*/
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)
{
pcap_if_t *curdev;
pcap_addr_t *curaddr, *prevaddr, *nextaddr;
if (add_or_find_if(&curdev, alldevs, name, flags, NULL, errbuf) == -1) {
/*
* Error - give up.
*/
return (-1);
}
if (curdev == NULL) {
/*
* Device wasn't added because it can't be opened.
* Not a fatal error.
*/
return (0);
}
/*
* "curdev" is an entry for this interface; add an entry for this
* address to its list of addresses.
*
* Allocate the new entry and fill it in.
*/
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);
}
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, "usb") != 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)strncpy(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;
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--)
{
strcpy((char*)tUstr, tAstr);
(char*)tUstr += strlen(tAstr) + 1;;
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 */
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