* Don't use getifaddrs(), since it's not portable; and rework the MAC address reading code.

getifaddr.c

@@ -91,41 +91,54 @@ getsysaddr(char * buf, int len)
 }
 
 int
-getifhwaddr(const char * ifname, char * buf, int len)
+getsyshwaddr(char * buf, int len)
 {
-	/* SIOCGIFADDR struct ifreq *  */
-	int s;
+	struct if_nameindex *ifaces, *if_idx;
+	unsigned char mac[6];
 	struct ifreq ifr;
-	int ifrlen;
-	unsigned char addr[6];
-	char mac_string[4];
-	int i;
-	ifrlen = sizeof(ifr);
-	if( len < 12 )
-	{
-		return -2;
-	}
-	s = socket(AF_INET, SOCK_DGRAM, 0);
-	if(s < 0)
-	{
-		DPRINTF(E_ERROR, L_GENERAL, "socket(PF_INET, SOCK_DGRAM): %s\n", strerror(errno));
-		return -1;
-	}
-	strncpy(ifr.ifr_name, ifname, IFNAMSIZ);
-	if(ioctl(s, SIOCGIFHWADDR, &ifr, &ifrlen) < 0)
-	{
-		DPRINTF(E_ERROR, L_GENERAL, "ioctl(s, SIOCGIFHWADDR, ...): %s\n", strerror(errno));
-		close(s);
-		return -1;
-	}
-	close(s);
+	int fd;
+	int ret = -1;
 
-	memmove( addr, ifr.ifr_hwaddr.sa_data, 6);
-	for (i=0; i<6; ++i) {
-		sprintf(mac_string, "%2.2x", addr[i]);
-		strcat(buf, mac_string);
+	memset(&mac, '\0', sizeof(mac));
+	/* Get the spatially unique node identifier */
+	fd = socket(AF_INET, SOCK_DGRAM, 0);
+	if( fd < 0 )
+		return(ret);
+
+	ifaces = if_nameindex();
+	if(!ifaces)
+		return(ret);
+
+	for(if_idx = ifaces+2; if_idx->if_index; if_idx++)
+	{
+		strncpy(ifr.ifr_name, if_idx->if_name, IFNAMSIZ);
+		if(ioctl(fd, SIOCGIFFLAGS, &ifr) < 0)
+			continue;
+		if(ifr.ifr_ifru.ifru_flags & IFF_LOOPBACK)
+			continue;
+		if( ioctl(fd, SIOCGIFHWADDR, &ifr) < 0 )
+			continue;
+		ret = 0;
+		break;
 	}
-	return 0;
+	if_freenameindex(ifaces);
+	close(fd);
+
+	if(ret == 0)
+	{
+		if(len > 12)
+		{
+			memmove(mac, ifr.ifr_hwaddr.sa_data, 6);
+			sprintf(buf, "%02x%02x%02x%02x%02x%02x",
+			        mac[0]&0xFF, mac[1]&0xFF, mac[2]&0xFF,
+			        mac[3]&0xFF, mac[4]&0xFF, mac[5]&0xFF);
+		}
+		else if(len == 6)
+		{
+			memmove(buf, ifr.ifr_hwaddr.sa_data, 6);
+		}
+	}
+	return ret;
 }
 
 int

getifaddr.h

@@ -19,7 +19,7 @@ int
 getsysaddr(char * buf, int len);
 
 int
-getifhwaddr(const char * ifname, char * buf, int len);
+getsyshwaddr(char * buf, int len);
 
 int
 get_remote_mac(struct in_addr ip_addr, unsigned char * mac);

minidlna.c

@@ -214,7 +214,7 @@ init(int argc, char * * argv)
 	/*const char * logfilename = 0;*/
 	const char * presurl = 0;
 	const char * optionsfile = "/etc/minidlna.conf";
-	char * mac_str = calloc(1, 64);
+	char mac_str[13];
 	char * string, * word;
 	enum media_types type;
 	char * path;
@@ -233,15 +233,13 @@ init(int argc, char * * argv)
 	}
 
 	/* set up uuid based on mac address */
-	if( (getifhwaddr("eth0", mac_str, 64) < 0) &&
-	    (getifhwaddr("eth1", mac_str, 64) < 0) )
+	if( getsyshwaddr(mac_str, sizeof(mac_str)) < 0 )
 	{
 		DPRINTF(E_OFF, L_GENERAL, "No MAC address found.  Falling back to generic UUID.\n");
 		strcpy(mac_str, "554e4b4e4f57");
 	}
 	strcpy(uuidvalue+5, "4d696e69-444c-164e-9d41-");
 	strncat(uuidvalue, mac_str, 12);
-	free(mac_str);
 
 	getfriendlyname(friendly_name, FRIENDLYNAME_MAX_LEN);
 	

uuid.c

@@ -22,6 +22,7 @@
 #include <sys/time.h>
 #include <errno.h>
 
+#include "getifaddr.h"
 #include "log.h"
 
 #define ETH_ALEN 6
@@ -109,55 +110,21 @@ generate_uuid(unsigned char uuid_out[16])
 {
 	static u_int64_t last_time_all;
 	static unsigned int clock_seq_started;
-	static char last_node[8] = { 0, 0, 0, 0, 0, 0, 0, 0 };
+	static char last_node[6] = { 0, 0, 0, 0, 0, 0 };
 
 	struct timespec ts;
 	u_int64_t time_all;
 	int inc_clock_seq = 0;
 
-	struct ifaddrs *ifaddr, *ifa;
 	unsigned char mac[6];
-	struct ifreq ifr;
-	int fd;
-
-	int found_mac = 0;
+	int mac_error;
 
 	memset(&mac, '\0', sizeof(mac));
 	/* Get the spatially unique node identifier */
-	fd = socket(AF_INET, SOCK_DGRAM, 0);
-	if( fd < 0 )
-		return -1;
 
-	if(getifaddrs(&ifaddr) == -1)
-	{
-		DPRINTF(E_ERROR, L_HTTP, "getifaddrs(): %s\n", strerror(errno));
-		return -1;
-	}
+	mac_error = getsyshwaddr((char *)mac, sizeof(mac));
 
-	for(ifa = ifaddr; ifa != NULL; ifa = ifa->ifa_next)
-	{
-		if(ifa->ifa_addr->sa_family != AF_PACKET)
-			continue;
-		if(ifa->ifa_flags & IFF_LOOPBACK)
-			continue;
-
-		strcpy(ifr.ifr_name, ifa->ifa_name);
-		if(strncmp(last_node, ifa->ifa_name, sizeof(last_node)) != 0)
-		{
-			inc_clock_seq = 1;
-			strncpy(last_node, ifa->ifa_name, sizeof(last_node));
-		}
-
-		if(ioctl(fd, SIOCGIFHWADDR, &ifr) == 0)
-			memmove(mac, ifr.ifr_hwaddr.sa_data, 6);
-
-		found_mac = 1;
-		break;
-	}
-	close(fd);
-	freeifaddrs(ifaddr);
-
-	if(found_mac)
+	if(!mac_error)
 	{
 		memcpy(&uuid_out[10], mac, ETH_ALEN);
 	}
@@ -172,6 +139,12 @@ generate_uuid(unsigned char uuid_out[16])
 		}
 	}
 
+	if(memcmp(last_node, uuid_out+10, 6) != 0)
+	{
+		inc_clock_seq = 1;
+		memcpy(last_node, uuid_out+10, 6);
+	}
+
 	/* Determine 60-bit timestamp value. For UUID version 1, this is
 	 * represented by Coordinated Universal Time (UTC) as a count of 100-
 	 * nanosecond intervals since 00:00:00.00, 15 October 1582 (the date of