/*
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[1024];
+ 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;
+ if(weight_str[consumed]) {
+ return false;
+ }
- for(i = 0; i < 4; i++) {
- if(x[i] > 255) {
- return false;
- }
+ *weight_separator = 0;
+ }
- subnet->net.ipv4.address.x[i] = x[i];
+ int prefixlength = -1;
+ char *prefixlength_separator = strchr(str, '/');
+
+ if(prefixlength_separator) {
+ char *prefixlength_str = prefixlength_separator + 1;
+
+ if(sscanf(prefixlength_str, "%d%n", &prefixlength, &consumed) < 1) {
+ return false;
}
- return true;
+ if(prefixlength_str[consumed]) {
+ return false;
+ }
+
+ *prefixlength_separator = 0;
+
+ if(prefixlength < 0) {
+ return false;
+ }
}
- 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) {
+ uint16_t x[8];
+
+ 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;
}
- subnet->type = SUBNET_IPV6;
- subnet->net.ipv6.prefixlength = l;
+ subnet->type = SUBNET_MAC;
subnet->weight = weight;
- for(i = 0; i < 8; i++) {
- subnet->net.ipv6.address.x[i] = htons(x[i]);
+ for(int i = 0; i < 6; i++) {
+ subnet->net.mac.address.x[i] = x[i];
}
return true;
}
- if(sscanf(subnetstr, "%hu.%hu.%hu.%hu#%d", &x[0], &x[1], &x[2], &x[3], &weight) >= 4) {
+ if(sscanf(str, "%hu.%hu.%hu.%hu%n", &x[0], &x[1], &x[2], &x[3], &consumed) >= 4 && !str[consumed]) {
+ if(prefixlength == -1) {
+ prefixlength = 32;
+ }
+
+ if(prefixlength > 32) {
+ return false;
+ }
+
subnet->type = SUBNET_IPV4;
- subnet->net.ipv4.prefixlength = 32;
+ subnet->net.ipv4.prefixlength = prefixlength;
subnet->weight = weight;
- for(i = 0; i < 4; i++) {
+ for(int i = 0; i < 4; i++) {
if(x[i] > 255) {
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;
-
- 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;
+ /* IPv6 */
- for(i = 0; i < 6; i++) {
- subnet->net.mac.address.x[i] = x[i];
- }
+ char *last_colon = strrchr(str, ':');
- 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(last_colon && sscanf(last_colon, ":%hu.%hu.%hu.%hu%n", &x[0], &x[1], &x[2], &x[3], &consumed) >= 4 && !last_colon[consumed]) {
+ /* Dotted quad suffix notation, convert to standard IPv6 notation */
+ for(int i = 0; i < 4; i++)
+ if(x[i] > 255) {
+ return false;
}
- if(colons > 7) {
- return false;
- }
+ snprintf(last_colon, sizeof(str) - (last_colon - str), ":%02x%02x:%02x%02x", x[0], x[1], x[2], x[3]);
+ }
- // Scan numbers before the double colon
- p = subnetstr;
+ char *double_colon = strstr(str, "::");
- for(i = 0; i < colons; i++) {
- if(*p == ':') {
- break;
- }
+ if(double_colon) {
+ /* Figure out how many zero groups we need to expand */
+ int zero_group_count = 8;
- x[i] = strtoul(p, &q, 0x10);
+ for(const char *cur = str; *cur; cur++)
+ if(*cur != ':') {
+ zero_group_count--;
- if(!q || p == q || *q != ':') {
- return false;
+ while(cur[1] && cur[1] != ':') {
+ cur++;
+ }
}
- p = ++q;
+ if(zero_group_count < 1) {
+ return false;
}
- p++;
- colons -= i;
+ /* Split the double colon in the middle to make room for zero groups */
+ double_colon++;
+ memmove(double_colon + (zero_group_count * 2 - 1), double_colon, strlen(double_colon) + 1);
- if(!i) {
- p++;
- colons--;
+ /* Write zero groups in the resulting gap, overwriting the second colon */
+ for(int i = 0; i < zero_group_count; i++) {
+ memcpy(&double_colon[i * 2], "0:", 2);
}
- if(!*p || *p == '/' || *p == '#') {
- colons--;
+ /* Remove any leading or trailing colons */
+ if(str[0] == ':') {
+ memmove(&str[0], &str[1], strlen(&str[1]) + 1);
}
- // Fill in the blanks
- for(; i < 8 - colons; i++) {
- x[i] = 0;
+ if(str[strlen(str) - 1] == ':') {
+ str[strlen(str) - 1] = 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(sscanf(str, "%hx:%hx:%hx:%hx:%hx:%hx:%hx:%hx%n",
+ &x[0], &x[1], &x[2], &x[3], &x[4], &x[5], &x[6], &x[7], &consumed) >= 8 && !str[consumed]) {
+ 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++) {
+ for(int i = 0; i < 8; i++) {
subnet->net.ipv6.address.x[i] = htons(x[i]);
}
}
// Prepare the SUBNET and WEIGHT variables
- if(envp[5]) {
- free(envp[5]);
- }
-
- if(envp[6]) {
- free(envp[6]);
- }
+ free(envp[5]);
+ free(envp[6]);
xasprintf(&envp[5], "SUBNET=%s", netstr);
xasprintf(&envp[6], "WEIGHT=%s", weight);
projects / oweals / tinc.git / blobdiff