tinc/src/subnet_parse.c

382 lines
8.1 KiB
C

/*
subnet_parse.c -- handle subnet parsing
Copyright (C) 2000-2012 Guus Sliepen <guus@tinc-vpn.org>,
2000-2005 Ivo Timmermans
This program is free software; you can redistribute it and/or modify
it under the terms of the GNU General Public License as published by
the Free Software Foundation; either version 2 of the License, or
(at your option) any later version.
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 along
with this program; if not, write to the Free Software Foundation, Inc.,
51 Franklin Street, Fifth Floor, Boston, MA 02110-1301 USA.
*/
#include "system.h"
#include "logger.h"
#include "net.h"
#include "netutl.h"
#include "subnet.h"
#include "utils.h"
#include "xalloc.h"
/* Subnet mask handling */
int maskcmp(const void *va, const void *vb, int masklen) {
int i, m, result;
const char *a = va;
const char *b = vb;
for(m = masklen, i = 0; m >= 8; m -= 8, i++) {
result = a[i] - b[i];
if(result)
return result;
}
if(m)
return (a[i] & (0x100 - (1 << (8 - m)))) -
(b[i] & (0x100 - (1 << (8 - m))));
return 0;
}
void mask(void *va, int masklen, int len) {
int i;
char *a = va;
i = masklen / 8;
masklen %= 8;
if(masklen)
a[i++] &= (0x100 - (1 << (8 - masklen)));
for(; i < len; i++)
a[i] = 0;
}
void maskcpy(void *va, const void *vb, int masklen, int len) {
int i, m;
char *a = va;
const char *b = vb;
for(m = masklen, i = 0; m >= 8; m -= 8, i++)
a[i] = b[i];
if(m) {
a[i] = b[i] & (0x100 - (1 << (8 - m)));
i++;
}
for(; i < len; i++)
a[i] = 0;
}
bool maskcheck(const void *va, int masklen, int len) {
int i;
const char *a = va;
i = masklen / 8;
masklen %= 8;
if(masklen && a[i++] & (0xff >> masklen))
return false;
for(; i < len; i++)
if(a[i] != 0)
return false;
return true;
}
/* Subnet comparison */
static int subnet_compare_mac(const subnet_t *a, const subnet_t *b) {
int result;
result = memcmp(&a->net.mac.address, &b->net.mac.address, sizeof a->net.mac.address);
if(result)
return result;
result = a->weight - b->weight;
if(result || !a->owner || !b->owner)
return result;
return strcmp(a->owner->name, b->owner->name);
}
static int subnet_compare_ipv4(const subnet_t *a, const subnet_t *b) {
int result;
result = b->net.ipv4.prefixlength - a->net.ipv4.prefixlength;
if(result)
return result;
result = memcmp(&a->net.ipv4.address, &b->net.ipv4.address, sizeof(ipv4_t));
if(result)
return result;
result = a->weight - b->weight;
if(result || !a->owner || !b->owner)
return result;
return strcmp(a->owner->name, b->owner->name);
}
static int subnet_compare_ipv6(const subnet_t *a, const subnet_t *b) {
int result;
result = b->net.ipv6.prefixlength - a->net.ipv6.prefixlength;
if(result)
return result;
result = memcmp(&a->net.ipv6.address, &b->net.ipv6.address, sizeof(ipv6_t));
if(result)
return result;
result = a->weight - b->weight;
if(result || !a->owner || !b->owner)
return result;
return strcmp(a->owner->name, b->owner->name);
}
int subnet_compare(const subnet_t *a, const subnet_t *b) {
int result;
result = a->type - b->type;
if(result)
return result;
switch (a->type) {
case SUBNET_MAC:
return subnet_compare_mac(a, b);
case SUBNET_IPV4:
return subnet_compare_ipv4(a, b);
case SUBNET_IPV6:
return subnet_compare_ipv6(a, b);
default:
logger(DEBUG_ALWAYS, LOG_ERR, "subnet_compare() was called with unknown subnet type %d, exitting!", a->type);
exit(1);
}
return 0;
}
/* Ascii representation of subnets */
bool str2net(subnet_t *subnet, const char *subnetstr) {
int i, l;
uint16_t x[8];
int weight = 10;
if(sscanf(subnetstr, "%hu.%hu.%hu.%hu/%d#%d",
&x[0], &x[1], &x[2], &x[3], &l, &weight) >= 5) {
if(l < 0 || l > 32)
return false;
subnet->type = SUBNET_IPV4;
subnet->net.ipv4.prefixlength = l;
subnet->weight = weight;
for(i = 0; i < 4; i++) {
if(x[i] > 255)
return false;
subnet->net.ipv4.address.x[i] = x[i];
}
return true;
}
if(sscanf(subnetstr, "%hx:%hx:%hx:%hx:%hx:%hx:%hx:%hx/%d#%d",
&x[0], &x[1], &x[2], &x[3], &x[4], &x[5], &x[6], &x[7],
&l, &weight) >= 9) {
if(l < 0 || l > 128)
return false;
subnet->type = SUBNET_IPV6;
subnet->net.ipv6.prefixlength = l;
subnet->weight = weight;
for(i = 0; i < 8; i++)
subnet->net.ipv6.address.x[i] = htons(x[i]);
return true;
}
if(sscanf(subnetstr, "%hu.%hu.%hu.%hu#%d", &x[0], &x[1], &x[2], &x[3], &weight) >= 4) {
subnet->type = SUBNET_IPV4;
subnet->net.ipv4.prefixlength = 32;
subnet->weight = weight;
for(i = 0; i < 4; i++) {
if(x[i] > 255)
return false;
subnet->net.ipv4.address.x[i] = x[i];
}
return true;
}
if(sscanf(subnetstr, "%hx:%hx:%hx:%hx:%hx:%hx:%hx:%hx#%d",
&x[0], &x[1], &x[2], &x[3], &x[4], &x[5], &x[6], &x[7], &weight) >= 8) {
subnet->type = SUBNET_IPV6;
subnet->net.ipv6.prefixlength = 128;
subnet->weight = weight;
for(i = 0; i < 8; i++)
subnet->net.ipv6.address.x[i] = htons(x[i]);
return true;
}
if(sscanf(subnetstr, "%hx:%hx:%hx:%hx:%hx:%hx#%d",
&x[0], &x[1], &x[2], &x[3], &x[4], &x[5], &weight) >= 6) {
subnet->type = SUBNET_MAC;
subnet->weight = weight;
for(i = 0; i < 6; i++)
subnet->net.mac.address.x[i] = x[i];
return true;
}
// IPv6 short form
if(strstr(subnetstr, "::")) {
const char *p;
char *q;
int colons = 0;
// Count number of colons
for(p = subnetstr; *p; p++)
if(*p == ':')
colons++;
if(colons > 7)
return false;
// Scan numbers before the double colon
p = subnetstr;
for(i = 0; i < colons; i++) {
if(*p == ':')
break;
x[i] = strtoul(p, &q, 0x10);
if(!q || p == q || *q != ':')
return false;
p = ++q;
}
p++;
colons -= i;
if(!i) {
p++;
colons--;
}
if(!*p || *p == '/' || *p == '#')
colons--;
// Fill in the blanks
for(; i < 8 - colons; i++)
x[i] = 0;
// Scan the remaining numbers
for(; i < 8; i++) {
x[i] = strtoul(p, &q, 0x10);
if(!q || p == q)
return false;
if(i == 7) {
p = q;
break;
}
if(*q != ':')
return false;
p = ++q;
}
l = 128;
if(*p == '/')
sscanf(p, "/%d#%d", &l, &weight);
else if(*p == '#')
sscanf(p, "#%d", &weight);
if(l < 0 || l > 128)
return false;
subnet->type = SUBNET_IPV6;
subnet->net.ipv6.prefixlength = l;
subnet->weight = weight;
for(i = 0; i < 8; i++)
subnet->net.ipv6.address.x[i] = htons(x[i]);
return true;
}
return false;
}
bool net2str(char *netstr, int len, const subnet_t *subnet) {
if(!netstr || !subnet) {
logger(DEBUG_ALWAYS, LOG_ERR, "net2str() was called with netstr=%p, subnet=%p!", netstr, subnet);
return false;
}
switch (subnet->type) {
case SUBNET_MAC:
snprintf(netstr, len, "%hx:%hx:%hx:%hx:%hx:%hx#%d",
subnet->net.mac.address.x[0],
subnet->net.mac.address.x[1],
subnet->net.mac.address.x[2],
subnet->net.mac.address.x[3],
subnet->net.mac.address.x[4],
subnet->net.mac.address.x[5],
subnet->weight);
break;
case SUBNET_IPV4:
snprintf(netstr, len, "%hu.%hu.%hu.%hu/%d#%d",
subnet->net.ipv4.address.x[0],
subnet->net.ipv4.address.x[1],
subnet->net.ipv4.address.x[2],
subnet->net.ipv4.address.x[3],
subnet->net.ipv4.prefixlength,
subnet->weight);
break;
case SUBNET_IPV6:
snprintf(netstr, len, "%hx:%hx:%hx:%hx:%hx:%hx:%hx:%hx/%d#%d",
ntohs(subnet->net.ipv6.address.x[0]),
ntohs(subnet->net.ipv6.address.x[1]),
ntohs(subnet->net.ipv6.address.x[2]),
ntohs(subnet->net.ipv6.address.x[3]),
ntohs(subnet->net.ipv6.address.x[4]),
ntohs(subnet->net.ipv6.address.x[5]),
ntohs(subnet->net.ipv6.address.x[6]),
ntohs(subnet->net.ipv6.address.x[7]),
subnet->net.ipv6.prefixlength,
subnet->weight);
break;
default:
logger(DEBUG_ALWAYS, LOG_ERR, "net2str() was called with unknown subnet type %d, exiting!", subnet->type);
exit(1);
}
return true;
}