/*
subnet_parse.c -- handle subnet parsing
- Copyright (C) 2000-2012 Guus Sliepen <guus@tinc-vpn.org>,
+ Copyright (C) 2000-2021 Guus Sliepen <guus@tinc-vpn.org>,
2000-2005 Ivo Timmermans
This program is free software; you can redistribute it and/or modify
#include "logger.h"
#include "net.h"
-#include "netutl.h"
#include "subnet.h"
-#include "utils.h"
-#include "xalloc.h"
+
+/* Changing this default will affect ADD_SUBNET messages - beware of inconsistencies between versions */
+static const int DEFAULT_WEIGHT = 10;
/* Subnet mask handling */
for(m = masklen, i = 0; m >= 8; m -= 8, i++) {
result = a[i] - b[i];
- if(result)
+
+ if(result) {
return result;
+ }
}
if(m)
return (a[i] & (0x100 - (1 << (8 - m)))) -
- (b[i] & (0x100 - (1 << (8 - m))));
+ (b[i] & (0x100 - (1 << (8 - m))));
return 0;
}
i = masklen / 8;
masklen %= 8;
- if(masklen)
+ if(masklen) {
a[i++] &= (0x100 - (1 << (8 - masklen)));
+ }
- for(; i < len; i++)
+ for(; i < len; i++) {
a[i] = 0;
+ }
}
void maskcpy(void *va, const void *vb, int masklen, int len) {
char *a = va;
const char *b = vb;
- for(m = masklen, i = 0; m >= 8; m -= 8, i++)
+ 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++)
+ for(; i < len; i++) {
a[i] = 0;
+ }
+}
+
+bool subnetcheck(const subnet_t subnet) {
+ if(((subnet.type == SUBNET_IPV4)
+ && !maskcheck(&subnet.net.ipv4.address, subnet.net.ipv4.prefixlength, sizeof(subnet.net.ipv4.address)))
+ || ((subnet.type == SUBNET_IPV6)
+ && !maskcheck(&subnet.net.ipv6.address, subnet.net.ipv6.prefixlength, sizeof(subnet.net.ipv6.address)))) {
+ return false;
+ }
+
+ return true;
}
bool maskcheck(const void *va, int masklen, int len) {
i = masklen / 8;
masklen %= 8;
- if(masklen && a[i++] & (0xff >> masklen))
+ if(masklen && a[i++] & (0xff >> masklen)) {
return false;
+ }
for(; i < len; i++)
- if(a[i] != 0)
+ if(a[i] != 0) {
return false;
+ }
return true;
}
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);
+ result = memcmp(&a->net.mac.address, &b->net.mac.address, sizeof(a->net.mac.address));
- if(result)
+ if(result) {
return result;
+ }
result = a->weight - b->weight;
- if(result || !a->owner || !b->owner)
+ if(result || !a->owner || !b->owner) {
return result;
+ }
return strcmp(a->owner->name, b->owner->name);
}
result = b->net.ipv4.prefixlength - a->net.ipv4.prefixlength;
- if(result)
+ if(result) {
return result;
+ }
result = memcmp(&a->net.ipv4.address, &b->net.ipv4.address, sizeof(ipv4_t));
- if(result)
+ if(result) {
return result;
+ }
result = a->weight - b->weight;
- if(result || !a->owner || !b->owner)
+ if(result || !a->owner || !b->owner) {
return result;
+ }
return strcmp(a->owner->name, b->owner->name);
}
result = b->net.ipv6.prefixlength - a->net.ipv6.prefixlength;
- if(result)
+ if(result) {
return result;
+ }
result = memcmp(&a->net.ipv6.address, &b->net.ipv6.address, sizeof(ipv6_t));
- if(result)
+ if(result) {
return result;
+ }
result = a->weight - b->weight;
- if(result || !a->owner || !b->owner)
+ 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;
+ int result = (int)a->type - (int)b->type;
- if(result)
+ if(result) {
return result;
+ }
- switch (a->type) {
+ 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);
/* Ascii representation of subnets */
bool str2net(subnet_t *subnet, const char *subnetstr) {
- int i, l;
- uint16_t x[8];
- int weight = 10;
+ char str[64];
+ strncpy(str, subnetstr, sizeof(str));
+ str[sizeof(str) - 1] = 0;
+ int consumed;
- 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;
+ int weight = DEFAULT_WEIGHT;
+ char *weight_separator = strchr(str, '#');
- subnet->type = SUBNET_IPV4;
- subnet->net.ipv4.prefixlength = l;
- subnet->weight = weight;
+ if(weight_separator) {
+ char *weight_str = weight_separator + 1;
- for(int i = 0; i < 4; i++) {
- if(x[i] > 255)
- return false;
- subnet->net.ipv4.address.x[i] = x[i];
+ if(sscanf(weight_str, "%d%n", &weight, &consumed) < 1) {
+ return false;
}
- 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)
+ if(weight_str[consumed]) {
return false;
+ }
- subnet->type = SUBNET_IPV6;
- subnet->net.ipv6.prefixlength = l;
- subnet->weight = weight;
+ *weight_separator = 0;
+ }
- for(i = 0; i < 8; i++)
- subnet->net.ipv6.address.x[i] = htons(x[i]);
+ int prefixlength = -1;
+ char *prefixlength_separator = strchr(str, '/');
- return true;
- }
+ if(prefixlength_separator) {
+ char *prefixlength_str = prefixlength_separator + 1;
- 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;
+ if(sscanf(prefixlength_str, "%d%n", &prefixlength, &consumed) < 1) {
+ return false;
+ }
- for(i = 0; i < 4; i++) {
- if(x[i] > 255)
- return false;
- subnet->net.ipv4.address.x[i] = x[i];
+ if(prefixlength_str[consumed]) {
+ return false;
}
- return true;
- }
+ *prefixlength_separator = 0;
- 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;
+ if(prefixlength < 0) {
+ return false;
+ }
+ }
- for(i = 0; i < 8; i++)
- subnet->net.ipv6.address.x[i] = htons(x[i]);
+ uint16_t x[8];
- return true;
- }
+ if(sscanf(str, "%hx:%hx:%hx:%hx:%hx:%hx%n", &x[0], &x[1], &x[2], &x[3], &x[4], &x[5], &consumed) >= 6 && !str[consumed]) {
+ /*
+ Normally we should check that each part has two digits to prevent ambiguities.
+ However, in old tinc versions net2str() will aggressively return MAC addresses with one-digit parts,
+ so we have to accept them otherwise we would be unable to parse ADD_SUBNET messages.
+ */
+ if(prefixlength >= 0) {
+ return false;
+ }
- 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++)
+ for(int 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(inet_pton(AF_INET, str, &subnet->net.ipv4.address)) {
+ if(prefixlength == -1) {
+ prefixlength = 32;
+ }
- if(colons > 7)
+ if(prefixlength > 32) {
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--;
- }
+ subnet->type = SUBNET_IPV4;
+ subnet->net.ipv4.prefixlength = prefixlength;
+ subnet->weight = weight;
- 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;
- }
+ return true;
+ }
- l = 128;
- if(*p == '/')
- sscanf(p, "/%d#%d", &l, &weight);
- else if(*p == '#')
- sscanf(p, "#%d", &weight);
+ if(inet_pton(AF_INET6, str, &subnet->net.ipv6.address)) {
+ if(prefixlength == -1) {
+ prefixlength = 128;
+ }
- if(l < 0 || l > 128)
+ if(prefixlength > 128) {
return false;
+ }
subnet->type = SUBNET_IPV6;
- subnet->net.ipv6.prefixlength = l;
+ subnet->net.ipv6.prefixlength = prefixlength;
subnet->weight = weight;
- for(i = 0; i < 8; i++)
- subnet->net.ipv6.address.x[i] = htons(x[i]);
-
return true;
}
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);
+ logger(DEBUG_ALWAYS, LOG_ERR, "net2str() was called with netstr=%p, subnet=%p!", (void *)netstr, (void *)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);
+ int result;
+ int prefixlength = -1;
+
+ switch(subnet->type) {
+ case SUBNET_MAC:
+ snprintf(netstr, len, "%02x:%02x:%02x:%02x:%02x:%02x",
+ 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]);
+ break;
+
+ case SUBNET_IPV4:
+ inet_ntop(AF_INET, &subnet->net.ipv4.address, netstr, len);
+ prefixlength = subnet->net.ipv4.prefixlength;
+
+ if(prefixlength == 32) {
+ prefixlength = -1;
+ }
+
+ break;
+
+ case SUBNET_IPV6: {
+ inet_ntop(AF_INET6, &subnet->net.ipv6.address, netstr, len);
+ prefixlength = subnet->net.ipv6.prefixlength;
+
+ if(prefixlength == 128) {
+ prefixlength = -1;
+ }
+
+ break;
+ }
+
+ default:
+ logger(DEBUG_ALWAYS, LOG_ERR, "net2str() was called with unknown subnet type %d, exiting!", subnet->type);
+ exit(1);
+ }
+
+ size_t used = strlen(netstr);
+ netstr += used;
+ len -= used;
+
+ if(prefixlength >= 0) {
+ result = snprintf(netstr, len, "/%d", prefixlength);
+ netstr += result;
+ len -= result;
+ }
+
+ if(subnet->weight != DEFAULT_WEIGHT) {
+ snprintf(netstr, len, "#%d", subnet->weight);
}
return true;