From: Vincent Bernat <vincent@bernat.im>
Date: Tue, 1 Dec 2015 08:01:17 +0000 (+0100)
Subject: interfaces: query permanent MAC address through ethtool
X-Git-Tag: 0.8.0~30
X-Git-Url: http://git.ipfire.org/?a=commitdiff_plain;h=d535fe053e0dee82199a1630c95512acbcc1e3ce;p=thirdparty%2Flldpd.git

interfaces: query permanent MAC address through ethtool

This is possible since 2.6.14. No need to parse a file. We still need to
do that as root as this is only allowed for mere mortals since
2.6.19 (and we would like to support 2.6.18). As a side note, it's
possible to query settings since 2.6.36 (so priv_ethtool is still
needed).
---

diff --git a/NEWS b/NEWS
index 973e49e8..55718b29 100644
--- a/NEWS
+++ b/NEWS
@@ -6,6 +6,9 @@ lldpd (0.8.0)
     + Change the numeric value for LLDP-MED policy L2 priority value
       for "Best effort" to 0 to match 802.1D-2004.
   * Change:
+    + Retrieve the permanent MAC address of an interface through
+      ethtool for Linux. This is is possible since 2.6.14, so no
+      compatibility layer is kept.
     + Running lldpd with "-d" will keep the process in foreground but
       logs will still go to syslog. To log to the console, add at
       least one "-d".
diff --git a/src/daemon/interfaces-linux.c b/src/daemon/interfaces-linux.c
index 8ac58c15..afad6485 100644
--- a/src/daemon/interfaces-linux.c
+++ b/src/daemon/interfaces-linux.c
@@ -237,88 +237,23 @@ iflinux_get_permanent_mac(struct lldpd *cfg,
     struct interfaces_device *iface)
 {
 	struct interfaces_device *master;
-	int f, state = 0;
-	FILE *netbond;
-	const char *slaveif = "Slave Interface: ";
-	const char *hwaddr = "Permanent HW addr: ";
 	u_int8_t mac[ETHER_ADDR_LEN];
-	char path[SYSFS_PATH_MAX];
-	char line[100];
 
+	/* We could do that for any interface, but let's do that only for
+	 * aggregates. */
 	if ((master = iface->upper) == NULL || master->type != IFACE_BOND_T)
 		return;
 
 	log_debug("interfaces", "get MAC address for %s",
 	    iface->name);
 
-	/* We have a bond, we need to query it to get real MAC addresses */
-	if (snprintf(path, SYSFS_PATH_MAX, "/proc/net/bonding/%s",
-		master->name) >= SYSFS_PATH_MAX) {
-		log_warnx("interfaces", "path truncated");
-		return;
-	}
-	if ((f = priv_open(path)) < 0) {
-		if (snprintf(path, SYSFS_PATH_MAX, "/proc/self/net/bonding/%s",
-			master->name) >= SYSFS_PATH_MAX) {
-			log_warnx("interfaces", "path truncated");
-			return;
-		}
-		f = priv_open(path);
-	}
-	if (f < 0) {
-		log_warnx("interfaces",
-		    "unable to find %s in /proc/net/bonding or /proc/self/net/bonding",
-		    master->name);
-		return;
-	}
-	if ((netbond = fdopen(f, "r")) == NULL) {
-		log_warn("interfaces", "unable to read stream from %s", path);
-		close(f);
+	if (priv_iface_mac(iface->name, mac, ETHER_ADDR_LEN) != 0) {
+		log_warnx("interfaces", "unable to get permanent MAC address for %s",
+		    iface->name);
 		return;
 	}
-	/* State 0:
-	     We parse the file to search "Slave Interface: ". If found, go to
-	     state 1.
-	   State 1:
-	     We parse the file to search "Permanent HW addr: ". If found, we get
-	     the mac.
-	*/
-	while (fgets(line, sizeof(line), netbond)) {
-		switch (state) {
-		case 0:
-			if (strncmp(line, slaveif, strlen(slaveif)) == 0) {
-				if (line[strlen(line)-1] == '\n')
-					line[strlen(line)-1] = '\0';
-				if (strcmp(iface->name,
-					line + strlen(slaveif)) == 0)
-					state++;
-			}
-			break;
-		case 1:
-			if (strncmp(line, hwaddr, strlen(hwaddr)) == 0) {
-				if (line[strlen(line)-1] == '\n')
-					line[strlen(line)-1] = '\0';
-				if (sscanf(line + strlen(hwaddr),
-					"%02hhx:%02hhx:%02hhx:%02hhx:%02hhx:%02hhx",
-					&mac[0], &mac[1], &mac[2],
-					&mac[3], &mac[4], &mac[5]) !=
-				    ETHER_ADDR_LEN) {
-					log_warn("interfaces", "unable to parse %s",
-					    line + strlen(hwaddr));
-					fclose(netbond);
-					return;
-				}
-				memcpy(iface->address, mac,
-				    ETHER_ADDR_LEN);
-				fclose(netbond);
-				return;
-			}
-			break;
-		}
-	}
-	log_warnx("interfaces", "unable to find real mac address for %s",
-	    iface->name);
-	fclose(netbond);
+	memcpy(iface->address, mac,
+	    ETHER_ADDR_LEN);
 }
 
 /* Fill up MAC/PHY for a given hardware port */
diff --git a/src/daemon/lldpd.h b/src/daemon/lldpd.h
index 07b93569..06ecf3bf 100644
--- a/src/daemon/lldpd.h
+++ b/src/daemon/lldpd.h
@@ -200,6 +200,8 @@ int    	 priv_open(char*);
 void	 asroot_open(void);
 int    	 priv_ethtool(char*, void*, size_t);
 void	 asroot_ethtool(void);
+int    	 priv_iface_mac(char*, void*, size_t);
+void	 asroot_iface_mac(void);
 #endif
 int    	 priv_iface_init(int, char *);
 int	 asroot_iface_init_os(int, char *, int *);
@@ -220,6 +222,7 @@ enum priv_cmd {
 	PRIV_IFACE_MULTICAST,
 	PRIV_IFACE_DESCRIPTION,
 	PRIV_IFACE_PROMISC,
+	PRIV_IFACE_MAC,
 	PRIV_SNMP_SOCKET,
 };
 
diff --git a/src/daemon/priv-linux.c b/src/daemon/priv-linux.c
index b919ba1b..0ae9a8af 100644
--- a/src/daemon/priv-linux.c
+++ b/src/daemon/priv-linux.c
@@ -53,7 +53,7 @@ priv_open(char *file)
 	return receive_fd(PRIV_UNPRIVILEGED);
 }
 
-/* Proxy for ethtool ioctl */
+/* Proxy for ethtool ioctl (GSET only) */
 int
 priv_ethtool(char *ifname, void *ethc, size_t length)
 {
@@ -71,13 +71,29 @@ priv_ethtool(char *ifname, void *ethc, size_t length)
 	return rc;
 }
 
+/* Proxy to get permanent MAC address */
+int
+priv_iface_mac(char *ifname, void *mac, size_t length)
+{
+	int rc, len;
+	enum priv_cmd cmd = PRIV_IFACE_MAC;
+	must_write(PRIV_UNPRIVILEGED, &cmd, sizeof(enum priv_cmd));
+	len = strlen(ifname);
+	must_write(PRIV_UNPRIVILEGED, &len, sizeof(int));
+	must_write(PRIV_UNPRIVILEGED, ifname, len);
+	priv_wait();
+	must_read(PRIV_UNPRIVILEGED, &rc, sizeof(int));
+	if (rc != 0)
+		return rc;
+	must_read(PRIV_UNPRIVILEGED, mac, length);
+	return rc;
+}
+
 void
 asroot_open()
 {
 	const char* authorized[] = {
 		"/proc/sys/net/ipv4/ip_forward",
-		"/proc/net/bonding/[^.][^/]*",
-		"/proc/self/net/bonding/[^.][^/]*",
 #ifdef ENABLE_OLDIES
 		SYSFS_CLASS_NET "[^.][^/]*/brforward",
 		SYSFS_CLASS_NET "[^.][^/]*/brport",
@@ -159,6 +175,40 @@ asroot_ethtool()
 	must_write(PRIV_PRIVILEGED, &ethc, sizeof(struct ethtool_cmd));
 }
 
+void
+asroot_iface_mac()
+{
+	struct ifreq ifr = {};
+	int len, rc, sock = -1;
+	char *ifname;
+	struct ethtool_perm_addr *epaddr;
+
+	must_read(PRIV_PRIVILEGED, &len, sizeof(int));
+	if ((ifname = (char*)malloc(len + 1)) == NULL)
+		fatal("privsep", NULL);
+	must_read(PRIV_PRIVILEGED, ifname, len);
+	ifname[len] = '\0';
+	strlcpy(ifr.ifr_name, ifname, sizeof(ifr.ifr_name));
+	free(ifname);
+
+	if ((epaddr = malloc(sizeof(struct ethtool_perm_addr) + ETHER_ADDR_LEN)) == NULL)
+		fatal("privsep", NULL);
+	epaddr->cmd = ETHTOOL_GPERMADDR;
+	epaddr->size = ETHER_ADDR_LEN;
+	ifr.ifr_data = (caddr_t)epaddr;
+	if (((rc = sock = socket(AF_INET, SOCK_DGRAM, 0)) == -1) ||
+	    (rc = ioctl(sock, SIOCETHTOOL, &ifr)) != 0) {
+		if (sock != -1) close(sock);
+		free(epaddr);
+		must_write(PRIV_PRIVILEGED, &rc, sizeof(int));
+		return;
+	}
+	close(sock);
+	must_write(PRIV_PRIVILEGED, &rc, sizeof(int));
+	must_write(PRIV_PRIVILEGED, epaddr->data, ETHER_ADDR_LEN);
+	free(epaddr);
+}
+
 int
 asroot_iface_init_os(int ifindex, char *name, int *fd)
 {
diff --git a/src/daemon/priv.c b/src/daemon/priv.c
index 5345f230..321e365b 100644
--- a/src/daemon/priv.c
+++ b/src/daemon/priv.c
@@ -388,6 +388,7 @@ static struct dispatch_actions actions[] = {
 #ifdef HOST_OS_LINUX
 	{PRIV_OPEN, asroot_open},
 	{PRIV_ETHTOOL, asroot_ethtool},
+	{PRIV_IFACE_MAC, asroot_iface_mac},
 #endif
 	{PRIV_IFACE_INIT, asroot_iface_init},
 	{PRIV_IFACE_MULTICAST, asroot_iface_multicast},
diff --git a/src/daemon/usr.sbin.lldpd.in b/src/daemon/usr.sbin.lldpd.in
index d459cd44..8d313f5a 100644
--- a/src/daemon/usr.sbin.lldpd.in
+++ b/src/daemon/usr.sbin.lldpd.in
@@ -58,8 +58,6 @@
 
   # Gather network information
   @{PROC}/sys/net/ipv4/ip_forward r,
-  @{PROC}/net/bonding/* r,
-  @{PROC}/self/net/bonding/* r,
   /sys/devices/virtual/dmi/** r,
   /sys/devices/pci**/net/*/ifalias r,
 }