X-Git-Url: https://www.tinc-vpn.org/git/browse?a=blobdiff_plain;f=src%2Fsubnet_parse.c;h=d5b84eb647f6fa710e4f3eeb9ab2ced28ded7ae2;hb=refs%2Fheads%2F1.1;hp=f980180019d0a42fd7429fbde65ccaf4a2306167;hpb=d917c8cb6b69475d568ccbe82389b9f2b3eb5e80;p=tinc

diff --git a/src/subnet_parse.c b/src/subnet_parse.c
index f9801800..e9271c12 100644
--- a/src/subnet_parse.c
+++ b/src/subnet_parse.c
@@ -1,6 +1,6 @@
 /*
     subnet_parse.c -- handle subnet parsing
-    Copyright (C) 2000-2012 Guus Sliepen <guus@tinc-vpn.org>,
+    Copyright (C) 2000-2021 Guus Sliepen <guus@tinc-vpn.org>,
                   2000-2005 Ivo Timmermans
 
     This program is free software; you can redistribute it and/or modify
@@ -22,75 +22,94 @@
 
 #include "logger.h"
 #include "net.h"
-#include "netutl.h"
 #include "subnet.h"
-#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) {
-	int i, m, result;
-	const char *a = va;
-	const char *b = vb;
+int maskcmp(const void *va, const void *vb, size_t masklen) {
+	size_t i, m;
+	const uint8_t *a = va;
+	const uint8_t *b = vb;
 
 	for(m = masklen, i = 0; m >= 8; m -= 8, i++) {
-		result = a[i] - b[i];
-		if(result)
+		int result = a[i] - b[i];
+
+		if(result) {
 			return result;
+		}
 	}
 
 	if(m)
 		return (a[i] & (0x100 - (1 << (8 - m)))) -
-			(b[i] & (0x100 - (1 << (8 - m))));
+		       (b[i] & (0x100 - (1 << (8 - m))));
 
 	return 0;
 }
 
-void mask(void *va, int masklen, int len) {
-	int i;
-	char *a = va;
+void mask(void *va, size_t masklen, size_t len) {
+	size_t i;
+	uint8_t *a = va;
 
 	i = masklen / 8;
 	masklen %= 8;
 
-	if(masklen)
+	if(masklen) {
 		a[i++] &= (0x100 - (1 << (8 - masklen)));
+	}
 
-	for(; i < len; i++)
+	for(; i < len; i++) {
 		a[i] = 0;
+	}
 }
 
-void maskcpy(void *va, const void *vb, int masklen, int len) {
-	int i, m;
-	char *a = va;
-	const char *b = vb;
+void maskcpy(void *va, const void *vb, size_t masklen, size_t len) {
+	size_t i, m;
+	uint8_t *a = va;
+	const uint8_t *b = vb;
 
-	for(m = masklen, i = 0; m >= 8; m -= 8, i++)
+	for(m = masklen, i = 0; m >= 8; m -= 8, i++) {
 		a[i] = b[i];
+	}
 
 	if(m) {
 		a[i] = b[i] & (0x100 - (1 << (8 - m)));
 		i++;
 	}
 
-	for(; i < len; i++)
+	for(; i < len; i++) {
 		a[i] = 0;
+	}
 }
 
-bool maskcheck(const void *va, int masklen, int len) {
-	int i;
-	const char *a = va;
+bool subnetcheck(const subnet_t subnet) {
+	if(((subnet.type == SUBNET_IPV4)
+	                && !maskcheck(&subnet.net.ipv4.address, subnet.net.ipv4.prefixlength, sizeof(subnet.net.ipv4.address)))
+	                || ((subnet.type == SUBNET_IPV6)
+	                    && !maskcheck(&subnet.net.ipv6.address, subnet.net.ipv6.prefixlength, sizeof(subnet.net.ipv6.address)))) {
+		return false;
+	}
+
+	return true;
+}
+
+bool maskcheck(const void *va, size_t masklen, size_t len) {
+	size_t i;
+	const uint8_t *a = va;
 
 	i = masklen / 8;
 	masklen %= 8;
 
-	if(masklen && a[i++] & (0xff >> masklen))
+	if(masklen && a[i++] & (0xff >> masklen)) {
 		return false;
+	}
 
 	for(; i < len; i++)
-		if(a[i] != 0)
+		if(a[i] != 0) {
 			return false;
+		}
 
 	return true;
 }
@@ -100,15 +119,17 @@ bool maskcheck(const void *va, int masklen, int len) {
 static int subnet_compare_mac(const subnet_t *a, const subnet_t *b) {
 	int result;
 
-	result = memcmp(&a->net.mac.address, &b->net.mac.address, sizeof a->net.mac.address);
+	result = memcmp(&a->net.mac.address, &b->net.mac.address, sizeof(a->net.mac.address));
 
-	if(result)
+	if(result) {
 		return result;
+	}
 
 	result = a->weight - b->weight;
 
-	if(result || !a->owner || !b->owner)
+	if(result || !a->owner || !b->owner) {
 		return result;
+	}
 
 	return strcmp(a->owner->name, b->owner->name);
 }
@@ -118,18 +139,21 @@ static int subnet_compare_ipv4(const subnet_t *a, const subnet_t *b) {
 
 	result = b->net.ipv4.prefixlength - a->net.ipv4.prefixlength;
 
-	if(result)
+	if(result) {
 		return result;
+	}
 
 	result = memcmp(&a->net.ipv4.address, &b->net.ipv4.address, sizeof(ipv4_t));
 
-	if(result)
+	if(result) {
 		return result;
+	}
 
 	result = a->weight - b->weight;
 
-	if(result || !a->owner || !b->owner)
+	if(result || !a->owner || !b->owner) {
 		return result;
+	}
 
 	return strcmp(a->owner->name, b->owner->name);
 }
@@ -139,37 +163,42 @@ static int subnet_compare_ipv6(const subnet_t *a, const subnet_t *b) {
 
 	result = b->net.ipv6.prefixlength - a->net.ipv6.prefixlength;
 
-	if(result)
+	if(result) {
 		return result;
+	}
 
 	result = memcmp(&a->net.ipv6.address, &b->net.ipv6.address, sizeof(ipv6_t));
 
-	if(result)
+	if(result) {
 		return result;
+	}
 
 	result = a->weight - b->weight;
 
-	if(result || !a->owner || !b->owner)
+	if(result || !a->owner || !b->owner) {
 		return result;
+	}
 
 	return strcmp(a->owner->name, b->owner->name);
 }
 
 int subnet_compare(const subnet_t *a, const subnet_t *b) {
-	int result;
-
-	result = a->type - b->type;
+	int result = (int)a->type - (int)b->type;
 
-	if(result)
+	if(result) {
 		return result;
+	}
 
-	switch (a->type) {
+	switch(a->type) {
 	case SUBNET_MAC:
 		return subnet_compare_mac(a, b);
+
 	case SUBNET_IPV4:
 		return subnet_compare_ipv4(a, b);
+
 	case SUBNET_IPV6:
 		return subnet_compare_ipv6(a, b);
+
 	default:
 		logger(DEBUG_ALWAYS, LOG_ERR, "subnet_compare() was called with unknown subnet type %d, exitting!", a->type);
 		exit(1);
@@ -181,201 +210,164 @@ int subnet_compare(const subnet_t *a, const subnet_t *b) {
 /* Ascii representation of subnets */
 
 bool str2net(subnet_t *subnet, const char *subnetstr) {
-	int i, l;
-	uint16_t x[8];
-	int weight = 10;
+	char str[64];
+	strncpy(str, subnetstr, sizeof(str));
+	str[sizeof(str) - 1] = 0;
+	int consumed;
 
-	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)
-			return false;
+	int weight = DEFAULT_WEIGHT;
+	char *weight_separator = strchr(str, '#');
 
-		subnet->type = SUBNET_IPV4;
-		subnet->net.ipv4.prefixlength = l;
-		subnet->weight = weight;
+	if(weight_separator) {
+		char *weight_str = weight_separator + 1;
 
-		for(int i = 0; i < 4; i++) {
-			if(x[i] > 255)
-				return false;
-			subnet->net.ipv4.address.x[i] = x[i];
+		if(sscanf(weight_str, "%d%n", &weight, &consumed) < 1) {
+			return false;
 		}
 
-		return true;
-	}
-
-	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)
+		if(weight_str[consumed]) {
 			return false;
+		}
 
-		subnet->type = SUBNET_IPV6;
-		subnet->net.ipv6.prefixlength = l;
-		subnet->weight = weight;
+		*weight_separator = 0;
+	}
 
-		for(i = 0; i < 8; i++)
-			subnet->net.ipv6.address.x[i] = htons(x[i]);
+	int prefixlength = -1;
+	char *prefixlength_separator = strchr(str, '/');
 
-		return true;
-	}
+	if(prefixlength_separator) {
+		char *prefixlength_str = prefixlength_separator + 1;
 
-	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(sscanf(prefixlength_str, "%d%n", &prefixlength, &consumed) < 1) {
+			return false;
+		}
 
-		for(i = 0; i < 4; i++) {
-			if(x[i] > 255)
-				return false;
-			subnet->net.ipv4.address.x[i] = x[i];
+		if(prefixlength_str[consumed]) {
+			return false;
 		}
 
-		return true;
-	}
+		*prefixlength_separator = 0;
 
-	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;
+		if(prefixlength < 0) {
+			return false;
+		}
+	}
 
-		for(i = 0; i < 8; i++)
-			subnet->net.ipv6.address.x[i] = htons(x[i]);
+	uint16_t x[8];
 
-		return true;
-	}
+	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;
+		}
 
-	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(inet_pton(AF_INET, str, &subnet->net.ipv4.address)) {
+		if(prefixlength == -1) {
+			prefixlength = 32;
+		}
 
-		if(colons > 7)
+		if(prefixlength > 32) {
 			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--;
-		}
+		subnet->type = SUBNET_IPV4;
+		subnet->net.ipv4.prefixlength = prefixlength;
+		subnet->weight = weight;
 
-		if(!*p || *p == '/' || *p == '#')
-			colons--;
-
-		// Fill in the blanks
-		for(; i < 8 - colons; i++)
-			x[i] = 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;
-		}
+		return true;
+	}
 
-		l = 128;
-		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;
 }
 
-bool net2str(char *netstr, int len, const subnet_t *subnet) {
+bool net2str(char *netstr, size_t len, const subnet_t *subnet) {
 	if(!netstr || !subnet) {
-		logger(DEBUG_ALWAYS, LOG_ERR, "net2str() was called with netstr=%p, subnet=%p!", netstr, subnet);
+		logger(DEBUG_ALWAYS, LOG_ERR, "net2str() was called with netstr=%p, subnet=%p!", (void *)netstr, (void *)subnet);
 		return false;
 	}
 
-	switch (subnet->type) {
-		case SUBNET_MAC:
-			snprintf(netstr, len, "%hx:%hx:%hx:%hx:%hx:%hx#%d",
-					 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);
-			break;
-
-		case SUBNET_IPV4:
-			snprintf(netstr, len, "%hu.%hu.%hu.%hu/%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);
-			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);
-			break;
-
-		default:
-			logger(DEBUG_ALWAYS, LOG_ERR, "net2str() was called with unknown subnet type %d, exiting!", subnet->type);
-			exit(1);
+	int result;
+	int prefixlength = -1;
+
+	switch(subnet->type) {
+	case SUBNET_MAC:
+		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]);
+		break;
+
+	case SUBNET_IPV4:
+		inet_ntop(AF_INET, &subnet->net.ipv4.address, netstr, len);
+		prefixlength = subnet->net.ipv4.prefixlength;
+
+		if(prefixlength == 32) {
+			prefixlength = -1;
+		}
+
+		break;
+
+	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(DEBUG_ALWAYS, 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 != DEFAULT_WEIGHT) {
+		snprintf(netstr, len, "#%d", subnet->weight);
 	}
 
 	return true;