Change netdev_get_in4() to re-check the IP address on each call.

As part of implementing switch stats, secchan wants to report the
IP address currently configured on an interface.  Caching it for
all time defeats that purpose.

diff --git a/lib/netdev.c b/lib/netdev.c
index 4eadc9c..d9ac425 100644 (file)
--- a/lib/netdev.c
+++ b/lib/netdev.c
@@ -75,7 +75,6 @@ struct netdev {
     int speed;
     int mtu;
     uint32_t features;
-    struct in_addr in4;
     struct in6_addr in6;
     int save_flags;             /* Initial device flags. */
     int changed_flags;          /* Flags that we changed. */
@@ -91,25 +90,6 @@ static int restore_flags(struct netdev *netdev);
 static int get_flags(const struct netdev *, int *flagsp);
 static int set_flags(struct netdev *, int flags);
 
-/* Obtains the IPv4 address for 'name' into 'in4'.  Returns true if
- * successful. */
-static bool
-get_ipv4_address(const char *name, struct in_addr *in4)
-{
-    struct ifreq ifr;
-
-    strncpy(ifr.ifr_name, name, sizeof ifr.ifr_name);
-    ifr.ifr_addr.sa_family = AF_INET;
-    if (ioctl(af_inet_sock, SIOCGIFADDR, &ifr) == 0) {
-        struct sockaddr_in *sin = (struct sockaddr_in *) &ifr.ifr_addr;
-        *in4 = sin->sin_addr;
-    } else {
-        in4->s_addr = INADDR_ANY;
-    }
-
-    return true;
-}
-
 /* Obtains the IPv6 address for 'name' into 'in6'. */
 static void
 get_ipv6_address(const char *name, struct in6_addr *in6)
@@ -228,7 +208,6 @@ netdev_open(const char *name, int ethertype, struct netdev **netdev_)
     struct ifreq ifr;
     unsigned int ifindex;
     uint8_t etheraddr[ETH_ADDR_LEN];
-    struct in_addr in4;
     struct in6_addr in6;
     int mtu;
     int error;
@@ -297,9 +276,6 @@ netdev_open(const char *name, int ethertype, struct netdev **netdev_)
     }
     mtu = ifr.ifr_mtu;
 
-    if (!get_ipv4_address(name, &in4)) {
-        goto error;
-    }
     get_ipv6_address(name, &in6);
 
     /* Allocate network device. */
@@ -309,7 +285,6 @@ netdev_open(const char *name, int ethertype, struct netdev **netdev_)
     netdev->fd = fd;
     memcpy(netdev->etheraddr, etheraddr, sizeof etheraddr);
     netdev->mtu = mtu;
-    netdev->in4 = in4;
     netdev->in6 = in6;
 
     /* Get speed, features. */
@@ -560,10 +535,22 @@ netdev_get_features(const struct netdev *netdev)
 bool
 netdev_get_in4(const struct netdev *netdev, struct in_addr *in4)
 {
+    struct ifreq ifr;
+    struct in_addr ip = { INADDR_ANY };
+
+    strncpy(ifr.ifr_name, netdev->name, sizeof ifr.ifr_name);
+    ifr.ifr_addr.sa_family = AF_INET;
+    if (ioctl(af_inet_sock, SIOCGIFADDR, &ifr) == 0) {
+        struct sockaddr_in *sin = (struct sockaddr_in *) &ifr.ifr_addr;
+        ip = sin->sin_addr;
+    } else {
+        VLOG_DBG("%s: ioctl(SIOCGIFADDR) failed: %s",
+                 netdev->name, strerror(errno));
+    }
     if (in4) {
-        *in4 = netdev->in4; 
+        *in4 = ip;
     }
-    return netdev->in4.s_addr != INADDR_ANY;
+    return ip.s_addr != INADDR_ANY;
 }
 
 static void
@@ -605,12 +592,9 @@ netdev_set_in4(struct netdev *netdev, struct in_addr addr, struct in_addr mask)
 
     error = do_set_addr(netdev, af_inet_sock,
                         SIOCSIFADDR, "SIOCSIFADDR", addr);
-    if (!error) {
-        netdev->in4 = addr;
-        if (addr.s_addr != INADDR_ANY) {
-            error = do_set_addr(netdev, af_inet_sock,
-                                SIOCSIFNETMASK, "SIOCSIFNETMASK", mask);
-        }
+    if (!error && addr.s_addr != INADDR_ANY) {
+        error = do_set_addr(netdev, af_inet_sock,
+                            SIOCSIFNETMASK, "SIOCSIFNETMASK", mask);
     }
     return error;
 }