X-Git-Url: https://www.tinc-vpn.org/git/browse?p=tinc;a=blobdiff_plain;f=src%2Fsubnet.c;h=154fd8048b16285ff79c8d8b3665ff72a5f84db4;hp=81dae5f3a6b6a0f257e3011036d01015915320ed;hb=HEAD;hpb=99763e34d52fcfe76b0bb9c7f3a17ace51cfdbfc

diff --git a/src/subnet.c b/src/subnet.c
index 81dae5f3..da69810c 100644
--- a/src/subnet.c
+++ b/src/subnet.c
@@ -1,6 +1,6 @@
 /*
     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
@@ -205,180 +205,100 @@ void subnet_del(node_t *n, subnet_t *subnet) {
 /* 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(prefixlength_str[consumed]) {
+			return false;
+		}
 
-	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;
+		*prefixlength_separator = 0;
 
-		for(i = 0; i < 4; i++) {
-			if(x[i] > 255) {
-				return false;
-			}
-
-			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;
-		}
-
-		// 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(inet_pton(AF_INET, str, &subnet->net.ipv4.address)) {
+		if(prefixlength == -1) {
+			prefixlength = 32;
 		}
 
-		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;
 	}
 
@@ -391,47 +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;
@@ -627,13 +558,8 @@ void subnet_update(node_t *owner, subnet_t *subnet, bool up) {
 			}
 
 			// 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);
@@ -659,7 +585,7 @@ void subnet_update(node_t *owner, subnet_t *subnet, bool up) {
 		}
 	}
 
-	for(i = 0; envp[i] && i < 9; i++) {
+	for(i = 0; i < 9; i++) {
 		free(envp[i]);
 	}
 }