Use ifAlias from newer Linux kernels if available.

From 2.6.28, Linux allows to attach a description to an interface. We
grab this description from /sys/class/net/$IFACE/ifalias if it exists
and is not empty and use it as port description. In this case,
interface name is used as port ID.

 PortID:    veth0 (ifName)
 PortDescr: Test interface

This closes ticket #10.

diff --git a/CHANGELOG b/CHANGELOG
index d360eb3278588eeb59da0a0ec327486f4113daad..4ef09fe80163fabdc0b424541816b70c07b573e4 100644 (file)
--- a/CHANGELOG
+++ b/CHANGELOG
@@ -8,6 +8,7 @@ lldpd (0.5.0)
     examples) or switch cores in the future. Sending/receive support
     is also abstracted.
   * Fix EDP VLAN handling
+  * Support of ifAlias with kernel >= 2.6.28
 
 lldpd (0.4)
 

diff --git a/src/interfaces.c b/src/interfaces.c
index 297fc0a0032ee0d0ae9b45931e98b64a978f9131..66e255af50c4c15d1b4922198643735230b81fb6 100644 (file)
--- a/src/interfaces.c
+++ b/src/interfaces.c
@@ -86,7 +86,7 @@ static void    iface_get_permanent_mac(struct lldpd *, struct lldpd_hardware *);
 static int      iface_minimal_checks(struct lldpd *, struct ifaddrs *);
 static int      iface_set_filter(const char *, int);
 
-static void     iface_portid(struct lldpd_hardware *);
+static void     iface_port_name_desc(struct lldpd_hardware *);
 static void     iface_macphy(struct lldpd_hardware *);
 static void     iface_mtu(struct lldpd *, struct lldpd_hardware *);
 static void     iface_multicast(struct lldpd *, const char *, int);
@@ -440,14 +440,51 @@ iface_set_filter(const char *name, int fd)
 
 /* Fill up port ID using hardware L2 address */
 static void
-iface_portid(struct lldpd_hardware *hardware)
+iface_port_name_desc(struct lldpd_hardware *hardware)
 {
        struct lldpd_port *port = &hardware->h_lport;
-       port->p_id_subtype = LLDP_PORTID_SUBTYPE_LLADDR;
-       if ((port->p_id = calloc(1, sizeof(hardware->h_lladdr))) == NULL)
+       char buffer[256];       /* 256 = IFALIASZ */
+       char path[SYSFS_PATH_MAX];
+       int f;
+
+       /* There are two cases:
+
+            1. We have a kernel recent enough to support ifAlias
+            _and_ a non empty ifAlias, then we will use it for
+            description and use ifname for port ID.
+
+            2. Otherwise, we will use the MAC address as ID and the
+            port name in description.
+       */
+
+       if ((snprintf(path, SYSFS_PATH_MAX,
+                   SYSFS_CLASS_NET "%s/ifalias", hardware->h_ifname)) >= SYSFS_PATH_MAX)
+               LLOG_WARNX("path truncated");
+       memset(buffer, 0, sizeof(buffer));
+       if (((f = priv_open(path)) < 0) || (read(f, buffer, sizeof(buffer)-1) < 1)) {
+               /* Case 2: MAC address and port name */
+               close(f);
+               port->p_id_subtype = LLDP_PORTID_SUBTYPE_LLADDR;
+               if ((port->p_id =
+                       calloc(1, sizeof(hardware->h_lladdr))) == NULL)
+                       fatal(NULL);
+               memcpy(port->p_id, hardware->h_lladdr,
+                   sizeof(hardware->h_lladdr));
+               port->p_id_len = sizeof(hardware->h_lladdr);
+               port->p_descr = strdup(hardware->h_ifname);
+               return;
+       }
+       /* Case 1: port name and port description */
+       close(f);
+       port->p_id_subtype = LLDP_PORTID_SUBTYPE_IFNAME;
+       port->p_id_len = strlen(hardware->h_ifname);
+       if ((port->p_id =
+               calloc(1, port->p_id_len)) == NULL)
                fatal(NULL);
-       memcpy(port->p_id, hardware->h_lladdr, sizeof(hardware->h_lladdr));
-       port->p_id_len = sizeof(hardware->h_lladdr);
+       memcpy(port->p_id, hardware->h_ifname, port->p_id_len);
+       if (buffer[strlen(buffer) - 1] == '\n')
+               buffer[strlen(buffer) - 1] = '\0';
+       port->p_descr = strdup(buffer);
 }
 
 /* Fill up MAC/PHY for a given hardware port */
@@ -675,11 +712,8 @@ lldpd_ifh_eth(struct lldpd *cfg, struct ifaddrs *ifap)
                lladdr = (u_int8_t*)(((struct sockaddr_ll *)ifa->ifa_addr)->sll_addr);
                memcpy(&hardware->h_lladdr, lladdr, sizeof(hardware->h_lladdr));
 
-               /* Port ID is the same as hardware address */
-               iface_portid(hardware);
-
-               /* Port description is its name */
-               port->p_descr = strdup(hardware->h_ifname);
+               /* Fill information about port */
+               iface_port_name_desc(hardware);
 
                /* Fill additional info */
                iface_macphy(hardware);
@@ -858,11 +892,8 @@ lldpd_ifh_bond(struct lldpd *cfg, struct ifaddrs *ifap)
                /* Get local address */
                iface_get_permanent_mac(cfg, hardware);
                
-               /* Port ID is the same as hardware address */
-               iface_portid(hardware);
-               
-               /* Port description is its name */
-               port->p_descr = strdup(hardware->h_ifname);
+               /* Fill information about port */
+               iface_port_name_desc(hardware);
                
                /* Fill additional info */
                port->p_aggregid = master;

diff --git a/src/priv.c b/src/priv.c
index 624d47c1c21eb57c93d8e2750f1ca382d956e0c8..3ab45d5dcf613423fa338a1b2021865d9ac69dff 100644 (file)
--- a/src/priv.c
+++ b/src/priv.c
@@ -257,6 +257,7 @@ asroot_open()
                SYSFS_CLASS_NET "[^.][^/]*/brforward",
                SYSFS_CLASS_NET "[^.][^/]*/brport",
                SYSFS_CLASS_NET "[^.][^/]*/brif/[^.][^/]*/port_no",
+               SYSFS_CLASS_NET "[^.][^/]*/ifalias",
                SYSFS_CLASS_DMI "product_version",
                SYSFS_CLASS_DMI "product_serial",
                SYSFS_CLASS_DMI "product_name",