suricata
util-ip.c
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1 /* Copyright (C) 2007-2013 Open Information Security Foundation
2  *
3  * You can copy, redistribute or modify this Program under the terms of
4  * the GNU General Public License version 2 as published by the Free
5  * Software Foundation.
6  *
7  * This program is distributed in the hope that it will be useful,
8  * but WITHOUT ANY WARRANTY; without even the implied warranty of
9  * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
10  * GNU General Public License for more details.
11  *
12  * You should have received a copy of the GNU General Public License
13  * version 2 along with this program; if not, write to the Free Software
14  * Foundation, Inc., 51 Franklin Street, Fifth Floor, Boston, MA
15  * 02110-1301, USA.
16  */
17 
18 /**
19  * \file
20  *
21  * \author Anoop Saldanha <anoopsaldanha@gmail.com>
22  * \author Duarte Silva <duarte.silva@serializing.me>
23  *
24  * IP addresses related utility functions
25  */
26 
27 #include "suricata-common.h"
28 #include "util-ip.h"
29 #include "util-byte.h"
30 #include "util-debug.h"
31 
32 /** \brief determine if a string is a valid ipv4 address
33  * \retval bool is addr valid?
34  */
35 bool IPv4AddressStringIsValid(const char *str)
36 {
37  int alen = 0;
38  char addr[4][4];
39  int dots = 0;
40 
41  memset(&addr, 0, sizeof(addr));
42 
43  uint32_t len = strlen(str);
44  uint32_t i = 0;
45  for (i = 0; i < len; i++) {
46  if (!(str[i] == '.' || isdigit(str[i]))) {
47  return false;
48  }
49  if (str[i] == '.') {
50  if (dots == 3) {
51  SCLogDebug("too many dots");
52  return false;
53  }
54  addr[dots][alen] = '\0';
55  dots++;
56  alen = 0;
57  } else {
58  if (alen >= 3) {
59  SCLogDebug("too long");
60  return false;
61  }
62  addr[dots][alen++] = str[i];
63  }
64  }
65  if (dots != 3)
66  return false;
67 
68  addr[dots][alen] = '\0';
69  for (int x = 0; x < 4; x++) {
70  uint8_t a;
71  if (StringParseUint8(&a, 10, 0, (const char *)addr[x]) < 0) {
72  SCLogDebug("invalid value for address byte: %s", addr[x]);
73  return false;
74  }
75  }
76  return true;
77 }
78 
79 /** \brief determine if a string is a valid ipv6 address
80  * \retval bool is addr valid?
81  */
82 bool IPv6AddressStringIsValid(const char *str)
83 {
84  int block_size = 0;
85  int sep = 0;
86  bool colon_seen = false;
87 
88  uint32_t len = strlen(str);
89  uint32_t i = 0;
90  for (i = 0; i < len && str[i] != 0; i++) {
91  if (!(str[i] == '.' || str[i] == ':' ||
92  isxdigit(str[i])))
93  return false;
94 
95  if (str[i] == ':') {
96  block_size = 0;
97  colon_seen = true;
98  sep++;
99  } else if (str[i] == '.') {
100  block_size = false;
101  sep++;
102  } else {
103  if (block_size == 4)
104  return false;
105  block_size++;
106  }
107  }
108 
109  if (!colon_seen)
110  return false;
111  if (sep > 7) {
112  SCLogDebug("too many seps %d", sep);
113  return false;
114  }
115  return true;
116 }
117 
118 /**
119  * \brief Validates an IPV4 address and returns the network endian arranged
120  * version of the IPV4 address
121  *
122  * \param addr Pointer to a character string containing an IPV4 address. A
123  * valid IPV4 address is a character string containing a dotted
124  * format of "ddd.ddd.ddd.ddd"
125  *
126  * \retval Pointer to an in_addr instance containing the network endian format
127  * of the IPV4 address
128  * \retval NULL if the IPV4 address is invalid
129  */
130 struct in_addr *ValidateIPV4Address(const char *addr_str)
131 {
132  struct in_addr *addr = NULL;
133 
134  if (!IPv4AddressStringIsValid(addr_str))
135  return NULL;
136 
137  if ( (addr = SCMalloc(sizeof(struct in_addr))) == NULL) {
138  FatalError("Fatal error encountered in ValidateIPV4Address. Exiting...");
139  }
140 
141  if (inet_pton(AF_INET, addr_str, addr) <= 0) {
142  SCFree(addr);
143  return NULL;
144  }
145 
146  return addr;
147 }
148 
149 /**
150  * \brief Validates an IPV6 address and returns the network endian arranged
151  * version of the IPV6 addresss
152  *
153  * \param addr Pointer to a character string containing an IPV6 address
154  *
155  * \retval Pointer to a in6_addr instance containing the network endian format
156  * of the IPV6 address
157  * \retval NULL if the IPV6 address is invalid
158  */
159 struct in6_addr *ValidateIPV6Address(const char *addr_str)
160 {
161  struct in6_addr *addr = NULL;
162 
163  if (!IPv6AddressStringIsValid(addr_str))
164  return NULL;
165 
166  if ( (addr = SCMalloc(sizeof(struct in6_addr))) == NULL) {
167  FatalError("Fatal error encountered in ValidateIPV6Address. Exiting...");
168  }
169 
170  if (inet_pton(AF_INET6, addr_str, addr) <= 0) {
171  SCFree(addr);
172  return NULL;
173  }
174 
175  return addr;
176 }
177 
178 /**
179  * \brief Culls the non-netmask portion of the IP address. For example an IP
180  * address 192.168.240.1 would be chopped to 192.168.224.0 against a
181  * netmask value of 19.
182  *
183  * \param stream Pointer the IP address that has to be masked
184  * \param netmask The netmask value (cidr) to which the IP address has to be culled
185  * \param key_bitlen The bitlen of the stream
186  */
187 void MaskIPNetblock(uint8_t *stream, int netmask, int key_bitlen)
188 {
189  uint32_t mask = 0;
190  int i = 0;
191  int bytes = key_bitlen / 8;
192 
193  for (i = 0; i < bytes; i++) {
194  mask = UINT_MAX;
195  if ( ((i + 1) * 8) > netmask) {
196  if ( ((i + 1) * 8 - netmask) < 8)
197  mask = UINT_MAX << ((i + 1) * 8 - netmask);
198  else
199  mask = 0;
200  }
201  stream[i] &= mask;
202  }
203 
204  return;
205 }
util-byte.h
len
uint8_t len
Definition: app-layer-dnp3.h:2
MaskIPNetblock
void MaskIPNetblock(uint8_t *stream, int netmask, int key_bitlen)
Culls the non-netmask portion of the IP address. For example an IP address 192.168....
Definition: util-ip.c:187
SCLogDebug
#define SCLogDebug(...)
Definition: util-debug.h:269
IPv4AddressStringIsValid
bool IPv4AddressStringIsValid(const char *str)
determine if a string is a valid ipv4 address
Definition: util-ip.c:35
StringParseUint8
int StringParseUint8(uint8_t *res, int base, size_t len, const char *str)
Definition: util-byte.c:361
util-debug.h
ValidateIPV4Address
struct in_addr * ValidateIPV4Address(const char *addr_str)
Validates an IPV4 address and returns the network endian arranged version of the IPV4 address.
Definition: util-ip.c:130
util-ip.h
IPv6AddressStringIsValid
bool IPv6AddressStringIsValid(const char *str)
determine if a string is a valid ipv6 address
Definition: util-ip.c:82
ValidateIPV6Address
struct in6_addr * ValidateIPV6Address(const char *addr_str)
Validates an IPV6 address and returns the network endian arranged version of the IPV6 addresss.
Definition: util-ip.c:159
suricata-common.h
FatalError
#define FatalError(...)
Definition: util-debug.h:502
SCMalloc
#define SCMalloc(sz)
Definition: util-mem.h:47
str
#define str(s)
Definition: suricata-common.h:280
SCFree
#define SCFree(p)
Definition: util-mem.h:61