Use inet_pton() to parse Subnets.

Nowadays all operating systems tinc runs on should support IPv6, so we
can rely on inet_pton() and inet_ntop() to convert IPv4 and IPv6
addresses. Use this instead of our own parsing code.

diff --git a/src/subnet.c b/src/subnet.c
index 154fd80..da69810 100644 (file)
--- a/src/subnet.c
+++ b/src/subnet.c
@@ -205,7 +205,7 @@ void subnet_del(node_t *n, subnet_t *subnet) {
 /* Ascii representation of subnets */
 
 bool str2net(subnet_t *subnet, const char *subnetstr) {
-       char str[1024];
+       char str[64];
        strncpy(str, subnetstr, sizeof(str));
        str[sizeof(str) - 1] = 0;
        int consumed;
@@ -270,7 +270,7 @@ bool str2net(subnet_t *subnet, const char *subnetstr) {
                return true;
        }
 
-       if(sscanf(str, "%hu.%hu.%hu.%hu%n", &x[0], &x[1], &x[2], &x[3], &consumed) >= 4 && !str[consumed]) {
+       if(inet_pton(AF_INET, str, &subnet->net.ipv4.address)) {
                if(prefixlength == -1) {
                        prefixlength = 32;
                }
@@ -283,71 +283,10 @@ bool str2net(subnet_t *subnet, const char *subnetstr) {
                subnet->net.ipv4.prefixlength = prefixlength;
                subnet->weight = weight;
 
-               for(int i = 0; i < 4; i++) {
-                       if(x[i] > 255) {
-                               return false;
-                       }
-
-                       subnet->net.ipv4.address.x[i] = x[i];
-               }
-
                return true;
        }
 
-       /* IPv6 */
-
-       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]);
-       }
-
-       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;
-               }
-
-               /* 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);
-
-               /* 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);
-               }
-
-               /* 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(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(inet_pton(AF_INET6, str, &subnet->net.ipv6.address)) {
                if(prefixlength == -1) {
                        prefixlength = 128;
                }
@@ -360,10 +299,6 @@ bool str2net(subnet_t *subnet, const char *subnetstr) {
                subnet->net.ipv6.prefixlength = prefixlength;
                subnet->weight = weight;
 
-               for(int i = 0; i < 8; i++) {
-                       subnet->net.ipv6.address.x[i] = htons(x[i]);
-               }
-
                return true;
        }
 
@@ -376,47 +311,58 @@ bool net2str(char *netstr, int len, const subnet_t *subnet) {
                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;