[pisa-src] r2526 - in trunk/tools/dhcp: mac2ip.c mac2ip.h
- From: Christoph Viethen <christoph.viethen@xxxxxxxxxxxxxx>
- To: pisa-src@xxxxxxxxxxxxx
- Date: Mon, 11 Apr 2011 13:06:24 +0200
Author: viethen
Date: Mon Apr 11 13:06:22 2011
New Revision: 2526
Log:
Get rid of custom mac2ip_ipv4_t, replacing it with the standard "struct
in_addr" type for IPv4 addresses. Advantages:
a) can now use standard htonl() and ntohl() for conversions between
network and host byte order instead of having to fiddle with array
elements
b) can entirely do without custom "string_to_ipv4_t()" conversion
routine (standard inet_pton() will do nicely)
Modified:
trunk/tools/dhcp/mac2ip.c
trunk/tools/dhcp/mac2ip.h
Modified: trunk/tools/dhcp/mac2ip.c
==============================================================================
--- trunk/tools/dhcp/mac2ip.c Fri Apr 8 02:42:41 2011 (r2525)
+++ trunk/tools/dhcp/mac2ip.c Mon Apr 11 13:06:22 2011 (r2526)
@@ -6,6 +6,7 @@
*/
#include "mac2ip.h"
+#include <arpa/inet.h>
#include <assert.h>
#include <inttypes.h>
#include <stdbool.h>
@@ -41,7 +42,7 @@
}
/* hash mac random ip */
-void hash_mac_to_rnd_ip_OAAT(const mac2ip_mac_t *mac, mac2ip_ipv4_t *ip)
+void hash_mac_to_rnd_ip_OAAT(const mac2ip_mac_t *mac, struct in_addr *ip)
{
const uint8_t uint8_max_value = 255;
time_t cur_time;
@@ -65,21 +66,7 @@
hash = jenkins_one_at_a_time_hash(mac_duplicate.x,
sizeof(mac_duplicate.x));
/* store the hash value (making sure it ends up in network byte order) */
- ip->x[0] = (hash & 0xff000000) >> 24;
- ip->x[1] = (hash & 0x00ff0000) >> 16;
- ip->x[2] = (hash & 0x0000ff00) >> 8;
- ip->x[3] = hash & 0x000000ff;
-}
-
-/* converts IPv4 address in the common dotted-quad notation to ipv4_t */
-/* returns -1 in case s.th. goes wrong, otherwise 0 */
-static int string_to_ipv4_t(const char *string, mac2ip_ipv4_t *ip)
-{
- if (sscanf(string, "%" SCNu8 ".%" SCNu8 ".%" SCNu8 ".%" SCNu8, &ip->x[0],
&ip->x[1], &ip->x[2], &ip->x[3]) == 4) {
- return 0;
- } else {
- return -1;
- }
+ ip->s_addr = htonl(hash);
}
static char *readline(FILE *fp, char **buf, size_t *buflen)
@@ -213,7 +200,7 @@
if (strcmp(variable, "lower_client_ip_bound") == 0) {
- if (string_to_ipv4_t(value, &bounds->lower_client.bound) == 0) {
+ if (inet_pton(AF_INET, value, &bounds->lower_client.bound.s_addr)
== 1) {
bounds->lower_client.valid = true;
retval++;
}
@@ -221,7 +208,7 @@
}
if (strcmp(variable, "upper_client_ip_bound") == 0) {
- if (string_to_ipv4_t(value, &bounds->upper_client.bound) == 0) {
+ if (inet_pton(AF_INET, value, &bounds->upper_client.bound.s_addr)
== 1) {
bounds->upper_client.valid = true;
retval++;
}
@@ -229,7 +216,7 @@
}
if (strcmp(variable, "lower_service_ip_bound") == 0) {
- if (string_to_ipv4_t(value, &bounds->lower_service.bound) == 0) {
+ if (inet_pton(AF_INET, value, &bounds->lower_service.bound.s_addr)
== 1) {
bounds->lower_service.valid = true;
retval++;
}
@@ -237,7 +224,7 @@
}
if (strcmp(variable, "upper_service_ip_bound") == 0) {
- if (string_to_ipv4_t(value, &bounds->upper_service.bound) == 0) {
+ if (inet_pton(AF_INET, value, &bounds->upper_service.bound.s_addr)
== 1) {
bounds->upper_service.valid = true;
retval++;
}
@@ -252,32 +239,27 @@
}
/* adjusts the ip to the given bounds */
-void adjust_ip_to_bounds(mac2ip_ipv4_t *ip, const mac2ip_ipv4_t *upper_bound,
const mac2ip_ipv4_t *lower_bound)
+void adjust_ip_to_bounds(struct in_addr *ip, const struct in_addr
*upper_bound, const struct in_addr *lower_bound)
{
uint32_t lower_bounds_value;
- uint32_t upper_bounds_value;
uint64_t num_bounds_ips;
uint32_t old_ip_value, new_ip_value;
/* determine number of IPs that fit within bounds */
- lower_bounds_value = ((lower_bound->x[0] * 256 + lower_bound->x[1]) * 256
+ lower_bound->x[2]) * 256 + lower_bound->x[3];
- upper_bounds_value = ((upper_bound->x[0] * 256 + upper_bound->x[1]) * 256
+ upper_bound->x[2]) * 256 + upper_bound->x[3];
- num_bounds_ips = upper_bounds_value - lower_bounds_value + 1;
+ lower_bounds_value = ntohl(lower_bound->s_addr);
+ num_bounds_ips = ntohl(upper_bound->s_addr) - lower_bounds_value + 1;
- /* convert the input IP into a numerical value */
- old_ip_value = ((ip->x[0] * 256 + ip->x[1]) * 256 + ip->x[2]) * 256 +
ip->x[3];
+ /* turn IP into host byte order value to enable the following calculation
*/
+ old_ip_value = ntohl(ip->s_addr);
/* old_ip_value modulo "number of IPs within the bounds" is offset within
the bounds */
new_ip_value = lower_bounds_value + (old_ip_value % num_bounds_ips);
- /* put the result back into "ip->x" array */
- ip->x[0] = (new_ip_value & 0xff000000) >> 24;
- ip->x[1] = (new_ip_value & 0x00ff0000) >> 16;
- ip->x[2] = (new_ip_value & 0x0000ff00) >> 8;
- ip->x[3] = new_ip_value & 0x000000ff;
+ /* ... and back into network byte order */
+ ip->s_addr = htonl(new_ip_value);
}
-int mac_to_ip(const mac2ip_mac_t *mac, mac2ip_ipv4_t *ip)
+int mac_to_ip(const mac2ip_mac_t *mac, struct in_addr *ip)
{
ip_bounds bounds;
@@ -293,6 +275,7 @@
return -1;
}
+ /* make the IP fit inbetween these bounds */
adjust_ip_to_bounds(ip, &bounds.upper_client.bound,
&bounds.lower_client.bound);
return 0;
Modified: trunk/tools/dhcp/mac2ip.h
==============================================================================
--- trunk/tools/dhcp/mac2ip.h Fri Apr 8 02:42:41 2011 (r2525)
+++ trunk/tools/dhcp/mac2ip.h Mon Apr 11 13:06:22 2011 (r2526)
@@ -20,19 +20,16 @@
#ifndef __MAC2IP_H__
#define __MAC2IP_H__
+#include <netinet/in.h>
#include <stdint.h>
-typedef struct mac2ip_ipv4_t {
- uint8_t x[4];
-} mac2ip_ipv4_t;
-
typedef struct mac2ip_mac_t {
uint8_t x[6];
} mac2ip_mac_t;
struct ip_bound {
- mac2ip_ipv4_t bound;
- _Bool valid;
+ struct in_addr bound;
+ _Bool valid;
};
typedef struct ip_bounds {
@@ -47,7 +44,7 @@
* configured in /etc/mac2ip.conf
* result will be stored in 'ip'
*/
-int mac_to_ip(const mac2ip_mac_t *, mac2ip_ipv4_t *);
+int mac_to_ip(const mac2ip_mac_t *, struct in_addr *);
int read_ip_bounds(ip_bounds *);
--
This is the pisa developer mailing list. Please also subscribe to the main pisa
list at:
//www.freelists.org/list/pisa
Other related posts:
- » [pisa-src] r2526 - in trunk/tools/dhcp: mac2ip.c mac2ip.h - Christoph Viethen
