#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 */
int maskcmp(const void *va, const void *vb, int masklen) {
/* 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)
+ char str[1024];
+ strncpy(str, subnetstr, sizeof(str));
+ str[sizeof str - 1] = 0;
+ int consumed;
+
+ int weight = DEFAULT_WEIGHT;
+ char *weight_separator = strchr(str, '#');
+ if (weight_separator) {
+ char *weight_str = weight_separator + 1;
+ if (sscanf(weight_str, "%d%n", &weight, &consumed) < 1)
return false;
+ if (weight_str[consumed])
+ return false;
+ *weight_separator = 0;
+ }
- subnet->type = SUBNET_IPV4;
- subnet->net.ipv4.prefixlength = l;
- subnet->weight = weight;
-
- for(int i = 0; i < 4; i++) {
- if(x[i] > 255)
- return false;
- 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;
+ if (prefixlength_str[consumed])
+ return false;
+ *prefixlength_separator = 0;
- return true;
+ 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 agressively 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++) {
- if(x[i] > 255)
+ for(int 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;
+ /* IPv6 */
- for(i = 0; i < 6; i++)
- subnet->net.mac.address.x[i] = x[i];
-
- return true;
+ char* last_colon = strrchr(str, ':');
+ 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;
+ snprintf(last_colon, sizeof str - (last_colon - str), ":%02x%02x:%02x%02x", x[0], x[1], x[2], x[3]);
}
- // 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)
+ char* double_colon = strstr(str, "::");
+ if (double_colon) {
+ /* Figure out how many zero groups we need to expand */
+ int zero_group_count = 8;
+ for (const char* cur = str; *cur; cur++)
+ if (*cur != ':') {
+ zero_group_count--;
+ while(cur[1] && cur[1] != ':')
+ cur++;
+ }
+ if (zero_group_count < 1)
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;
+ /* 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);
- // 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;
- }
+ /* 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);
- l = 128;
- if(*p == '/')
- sscanf(p, "/%d#%d", &l, &weight);
- else if(*p == '#')
- sscanf(p, "#%d", &weight);
+ /* Remove any leading or trailing colons */
+ if (str[0] == ':')
+ memmove(&str[0], &str[1], strlen(&str[1]) + 1);
+ if (str[strlen(str) - 1] == ':')
+ str[strlen(str) - 1] = 0;
+ }
- if(l < 0 || l > 128)
+ 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 (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]);
-
return true;
}
return false;
}
+ int result;
+ int prefixlength = -1;
switch (subnet->type) {
case SUBNET_MAC:
- snprintf(netstr, len, "%hx:%hx:%hx:%hx:%hx:%hx#%d",
+ result = 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]);
+ netstr += result;
+ len -= result;
break;
case SUBNET_IPV4:
- snprintf(netstr, len, "%hu.%hu.%hu.%hu/%d#%d",
+ result = snprintf(netstr, len, "%u.%u.%u.%u",
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);
+ subnet->net.ipv4.address.x[3]);
+ netstr += result;
+ len -= result;
+ prefixlength = subnet->net.ipv4.prefixlength;
+ if (prefixlength == 32)
+ prefixlength = -1;
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);
+ case SUBNET_IPV6: {
+ /* Find the longest sequence of consecutive zeroes */
+ int max_zero_length = 0;
+ int max_zero_length_index = 0;
+ int current_zero_length = 0;
+ int current_zero_length_index = 0;
+ for (int i = 0; i < 8; i++) {
+ if (subnet->net.ipv6.address.x[i] != 0)
+ current_zero_length = 0;
+ else {
+ if (current_zero_length == 0)
+ current_zero_length_index = i;
+ current_zero_length++;
+ if (current_zero_length > max_zero_length) {
+ max_zero_length = current_zero_length;
+ max_zero_length_index = current_zero_length_index;
+ }
+ }
+ }
+
+ /* Print the address */
+ for (int i = 0; i < 8;) {
+ if (max_zero_length > 1 && max_zero_length_index == i) {
+ /* Shorten the representation as per RFC 5952 */
+ const char* const FORMATS[] = { "%.1s", "%.2s", "%.3s" };
+ const char* const* format = &FORMATS[0];
+ if (i == 0)
+ format++;
+ if (i + max_zero_length == 8)
+ format++;
+ result = snprintf(netstr, len, *format, ":::");
+ i += max_zero_length;
+ } else {
+ result = snprintf(netstr, len, "%hx:", ntohs(subnet->net.ipv6.address.x[i]));
+ i++;
+ }
+ netstr += result;
+ len -= result;
+ }
+
+ /* Remove the trailing colon */
+ netstr--;
+ len++;
+ *netstr = 0;
+
+ 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);
}
+ 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;
}
projects / tinc / blobdiff