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/* Copyright (C) 2007-2013 Open Information Security Foundation
*
* You can copy, redistribute or modify this Program under the terms of
* the GNU General Public License version 2 as published by the Free
* Software Foundation.
*
* This program is distributed in the hope that it will be useful,
* but WITHOUT ANY WARRANTY; without even the implied warranty of
* MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
* GNU General Public License for more details.
*
* You should have received a copy of the GNU General Public License
* version 2 along with this program; if not, write to the Free Software
* Foundation, Inc., 51 Franklin Street, Fifth Floor, Boston, MA
* 02110-1301, USA.
*/
/**
* \file
*
* \author Anoop Saldanha <anoopsaldanha@gmail.com>
* \author Duarte Silva <duarte.silva@serializing.me>
*
* IP addresses related utility functions
*/
#include "suricata-common.h"
#include "util-ip.h"
#include "util-byte.h"
#include "util-debug.h"
/** \brief determine if a string is a valid ipv4 address
* \retval bool is addr valid?
*/
bool IPv4AddressStringIsValid(const char *str)
{
int alen = 0;
char addr[4][4];
int dots = 0;
memset(&addr, 0, sizeof(addr));
uint32_t len = strlen(str);
uint32_t i = 0;
for (i = 0; i < len; i++) {
if (!(str[i] == '.' || isdigit(str[i]))) {
return false;
}
if (str[i] == '.') {
if (dots == 3) {
SCLogDebug("too many dots");
return false;
}
addr[dots][alen] = '\0';
dots++;
alen = 0;
} else {
if (alen >= 3) {
SCLogDebug("too long");
return false;
}
addr[dots][alen++] = str[i];
}
}
if (dots != 3)
return false;
addr[dots][alen] = '\0';
for (int x = 0; x < 4; x++) {
uint8_t a;
if (StringParseUint8(&a, 10, 0, (const char *)addr[x]) < 0) {
SCLogDebug("invalid value for address byte: %s", addr[x]);
return false;
}
}
return true;
}
/** \brief determine if a string is a valid ipv6 address
* \retval bool is addr valid?
*/
bool IPv6AddressStringIsValid(const char *str)
{
int block_size = 0;
int sep = 0;
bool colon_seen = false;
uint32_t len = strlen(str);
uint32_t i = 0;
for (i = 0; i < len && str[i] != 0; i++) {
if (!(str[i] == '.' || str[i] == ':' ||
isxdigit(str[i])))
return false;
if (str[i] == ':') {
block_size = 0;
colon_seen = true;
sep++;
} else if (str[i] == '.') {
block_size = false;
sep++;
} else {
if (block_size == 4)
return false;
block_size++;
}
}
if (!colon_seen)
return false;
if (sep > 7) {
SCLogDebug("too many seps %d", sep);
return false;
}
return true;
}
/**
* \brief Validates an IPV4 address and returns the network endian arranged
* version of the IPV4 address
*
* \param addr Pointer to a character string containing an IPV4 address. A
* valid IPV4 address is a character string containing a dotted
* format of "ddd.ddd.ddd.ddd"
*
* \retval Pointer to an in_addr instance containing the network endian format
* of the IPV4 address
* \retval NULL if the IPV4 address is invalid
*/
struct in_addr *ValidateIPV4Address(const char *addr_str)
{
struct in_addr *addr = NULL;
if (!IPv4AddressStringIsValid(addr_str))
return NULL;
if ( (addr = SCMalloc(sizeof(struct in_addr))) == NULL) {
FatalError("Fatal error encountered in ValidateIPV4Address. Exiting...");
}
if (inet_pton(AF_INET, addr_str, addr) <= 0) {
SCFree(addr);
return NULL;
}
return addr;
}
/**
* \brief Validates an IPV6 address and returns the network endian arranged
* version of the IPV6 address
*
* \param addr Pointer to a character string containing an IPV6 address
*
* \retval Pointer to a in6_addr instance containing the network endian format
* of the IPV6 address
* \retval NULL if the IPV6 address is invalid
*/
struct in6_addr *ValidateIPV6Address(const char *addr_str)
{
struct in6_addr *addr = NULL;
if (!IPv6AddressStringIsValid(addr_str))
return NULL;
if ( (addr = SCMalloc(sizeof(struct in6_addr))) == NULL) {
FatalError("Fatal error encountered in ValidateIPV6Address. Exiting...");
}
if (inet_pton(AF_INET6, addr_str, addr) <= 0) {
SCFree(addr);
return NULL;
}
return addr;
}
/**
* \brief Culls the non-netmask portion of the IP address. For example an IP
* address 192.168.240.1 would be chopped to 192.168.224.0 against a
* netmask value of 19.
*
* \param stream Pointer the IP address that has to be masked
* \param netmask The netmask value (cidr) to which the IP address has to be culled
* \param key_bitlen The bitlen of the stream
*/
void MaskIPNetblock(uint8_t *stream, int netmask, int key_bitlen)
{
uint32_t mask = 0;
int i = 0;
int bytes = key_bitlen / 8;
for (i = 0; i < bytes; i++) {
mask = UINT_MAX;
if ( ((i + 1) * 8) > netmask) {
if ( ((i + 1) * 8 - netmask) < 8)
mask = UINT_MAX << ((i + 1) * 8 - netmask);
else
mask = 0;
}
stream[i] &= mask;
}
return;
}
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