/*
subnet.c -- handle subnet lookups and lists
- Copyright (C) 2000-2014 Guus Sliepen <guus@tinc-vpn.org>,
+ Copyright (C) 2000-2019 Guus Sliepen <guus@tinc-vpn.org>,
2000-2005 Ivo Timmermans
This program is free software; you can redistribute it and/or modify
/* Ascii representation of subnets */
bool str2net(subnet_t *subnet, const char *subnetstr) {
- int i, l;
- uint16_t x[8];
+ char str[64];
+ strncpy(str, subnetstr, sizeof(str));
+ str[sizeof(str) - 1] = 0;
+ int consumed;
+
int weight = 10;
+ char *weight_separator = strchr(str, '#');
+
+ if(weight_separator) {
+ char *weight_str = weight_separator + 1;
- 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) {
+ if(sscanf(weight_str, "%d%n", &weight, &consumed) < 1) {
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];
+ if(weight_str[consumed]) {
+ return false;
}
- return true;
+ *weight_separator = 0;
}
- 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;
- }
+ int prefixlength = -1;
+ char *prefixlength_separator = strchr(str, '/');
- subnet->type = SUBNET_IPV6;
- subnet->net.ipv6.prefixlength = l;
- subnet->weight = weight;
+ if(prefixlength_separator) {
+ char *prefixlength_str = prefixlength_separator + 1;
- for(i = 0; i < 8; i++) {
- subnet->net.ipv6.address.x[i] = htons(x[i]);
+ if(sscanf(prefixlength_str, "%d%n", &prefixlength, &consumed) < 1) {
+ return false;
}
- 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;
+ if(prefixlength_str[consumed]) {
+ return false;
+ }
- for(i = 0; i < 4; i++) {
- if(x[i] > 255) {
- return false;
- }
+ *prefixlength_separator = 0;
- subnet->net.ipv4.address.x[i] = x[i];
+ if(prefixlength < 0) {
+ return false;
}
-
- 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;
+ uint16_t x[8];
- for(i = 0; i < 8; i++) {
- subnet->net.ipv6.address.x[i] = htons(x[i]);
+ 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;
}
- 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++) {
+ 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(colons > 7) {
- return false;
+ if(inet_pton(AF_INET, str, &subnet->net.ipv4.address)) {
+ if(prefixlength == -1) {
+ prefixlength = 32;
}
- // 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;
+ if(prefixlength > 32) {
+ return false;
}
- // 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;
- }
+ subnet->type = SUBNET_IPV4;
+ subnet->net.ipv4.prefixlength = prefixlength;
+ subnet->weight = weight;
- l = 128;
+ return true;
+ }
- 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;
}
return false;
}
+ int result;
+ int prefixlength = -1;
+
switch(subnet->type) {
case SUBNET_MAC:
- snprintf(netstr, len, "%x:%x:%x:%x:%x:%x#%d",
+ 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],
- subnet->weight);
+ subnet->net.mac.address.x[5]);
break;
case SUBNET_IPV4:
- snprintf(netstr, len, "%u.%u.%u.%u/%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);
+ inet_ntop(AF_INET, &subnet->net.ipv4.address, netstr, len);
+ prefixlength = subnet->net.ipv4.prefixlength;
+
+ if(prefixlength == 32) {
+ prefixlength = -1;
+ }
+
break;
- case SUBNET_IPV6:
- snprintf(netstr, len, "%x:%x:%x:%x:%x:%x:%x:%x/%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);
+ 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(LOG_ERR,
- "net2str() was called with unknown subnet type %d, exiting!",
- subnet->type);
- exit(0);
+ logger(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 != 10) {
+ snprintf(netstr, len, "#%d", subnet->weight);
}
return true;