* isys/nl.c (netlink_format_ip_addr): Rewrote to malloc for space

   in the function and handle IPv4 and IPv6 address lengths more
   gracefully.

   * isys/nl.c (netlink_interfaces_ip2str): Added function to return the
   IP address of the specified device name. If you have an IPv4 address
   for the device, that's returned. If you only have an IPv6 address,
   that's returned. The string returned is the human-readable IP addr.

   * isys/nl.c (_netlink_interfaces_elem_find): Renamed the
   _netlink_interfaces_elem_mac2str function since it's a generic intf
   search routine.

   * isys/nl.c (netlink_init_interfaces_list): If there is no IPv6
   address, memset intfinfo->ip6_addr to all zeros.

   * isys/nl.h: Prototype updates.

1 files changed, 84 insertions, 16 deletions

diff --git a/isys/nl.c b/isys/nl.c
index b049a4da8..68ce642fd 100644
--- a/isys/nl.c
+++ b/isys/nl.c
@@ -73,19 +73,31 @@ char *netlink_format_mac_addr(char *buf, unsigned char *mac) {
  * @return A pointer to buf.
  */
 char *netlink_format_ip_addr(int family, interface_info_t *intf, char *buf) {
-   char ipbuf[256];
+   int iplen;
+
+   if (family == AF_INET6)
+      iplen = INET6_ADDRSTRLEN;
+   else
+      iplen = INET_ADDRSTRLEN;
+
+   if (buf == NULL) {
+      if ((buf = malloc(iplen)) == NULL) {
+         perror("malloc in netlink_format_ip_addr");
+         return NULL;
+      }
+
+      memset(buf, 0, iplen);
+   }
 
-   memset(ipbuf, 0, sizeof(ipbuf));
    switch (family) {
       case AF_INET:
-         inet_ntop(family, &(intf->ip_addr), ipbuf, sizeof(ipbuf));
+         inet_ntop(family, &(intf->ip_addr), buf, iplen);
          break;
       case AF_INET6:
-         inet_ntop(family, &(intf->ip6_addr), ipbuf, sizeof(ipbuf));
+         inet_ntop(family, &(intf->ip6_addr), buf, iplen);
          break;
    }
 
-   memcpy(buf, ipbuf, sizeof(ipbuf));
    return buf;
 }
 
@@ -342,10 +354,8 @@ int netlink_init_interfaces_list(void) {
 
          /* get the IPv6 address of this interface (if any) */
          r = netlink_get_interface_ip(intfinfo->i,AF_INET6,&intfinfo->ip6_addr);
-/* XXX: why this no work?
          if (r == -1)
-            intfinfo->ip6_addr.s6_addr = 0;
-*/
+            memset(intfinfo->ip6_addr.s6_addr, 0, sizeof(intfinfo->ip6_addr.s6_addr));
 
          /* add this interface */
          interfaces = g_slist_append(interfaces, intfinfo);
@@ -360,6 +370,56 @@ int netlink_init_interfaces_list(void) {
 }
 
 /**
+ * Take the cylon-readable IP address for the specified device and format
+ * it for human reading.  NOTE:  This function will check for IPv6 and IPv4
+ * addresses.  In the case where the interface has both, the IPv4 address
+ * is returned.  The only way you will get an IPv6 address from this function
+ * is if that's the only address configured for the interface.
+ *
+ * @param ifname The interface name (e.g., eth0).
+ * @return The human-readable IP address (either IPv4 or IPv6) or NULL on
+ *         error/no match.
+ */
+char *netlink_interfaces_ip2str(char *ifname) {
+   char *ret = NULL;
+   GSList *e;
+   interface_info_t *intf;
+
+   if (ifname == NULL)
+      return NULL;
+
+   /* init the interfaces list if it's empty */
+   if (interfaces == NULL) {
+      if (netlink_init_interfaces_list() == -1) {
+         perror("netlink_init_interfaces_list in netlink_interface_mac2str");
+         return NULL;
+      }
+   }
+
+   e = g_slist_find_custom(interfaces,ifname,&_netlink_interfaces_elem_find);
+   if (e == NULL) {
+      return NULL;
+   } else {
+      intf = (interface_info_t *) e->data;
+
+      if (intf->ip_addr.s_addr == 0 && intf->ip6_addr.s6_addr[0] == 0)
+         /* neither IP set, return null */
+         ret = NULL;
+      else if (intf->ip_addr.s_addr == 0 && intf->ip6_addr.s6_addr[0] != 0)
+         /* only IPv6 addr, return that */
+         ret = netlink_format_ip_addr(AF_INET6, intf, ret);
+      else if (intf->ip_addr.s_addr != 0)
+         /* if IPv4 is set, return that (regardless of IPv6 value) */
+         ret = netlink_format_ip_addr(AF_INET, intf, ret);
+      else
+         /* we have no idea what happened, return NULL */
+         ret = NULL;
+
+      return ret;
+   }
+}
+
+/**
  * Take the cylon-readable MAC address for the specified device and
  * format it for human reading.
  *
@@ -383,7 +443,7 @@ char *netlink_interfaces_mac2str(char *ifname) {
       }
    }
 
-   e = g_slist_find_custom(interfaces,ifname,&_netlink_interfaces_elem_mac2str);
+   e = g_slist_find_custom(interfaces,ifname,&_netlink_interfaces_elem_find);
    if (e == NULL) {
       return NULL;
    } else {
@@ -415,12 +475,13 @@ void _netlink_interfaces_elem_free(gpointer data, gpointer user_data) {
 }
 
 /**
- * Callback function for netlink_interfaces_mac2str.  Compares one list
- * element to the specified interface name.
+ * Compares one list element to the specified interface name.  Callback
+ * function used to locate a list element by interface name.
  *
  * @see netlink_interfaces_mac2str
+ * @see netlink_interfaces_ip2str
  */
-gint _netlink_interfaces_elem_mac2str(gconstpointer a, gconstpointer b) {
+gint _netlink_interfaces_elem_find(gconstpointer a, gconstpointer b) {
    char *ifname = (char *) b;
    GSList *elemdata = (GSList *) a;
    interface_info_t *intf;
@@ -434,18 +495,25 @@ gint _netlink_interfaces_elem_mac2str(gconstpointer a, gconstpointer b) {
 
 #ifdef TESTING
 void print_interfaces(gpointer data, gpointer user_data) {
-   char buf[20];
-   char ipbuf[256];
+   char *buf = NULL;
+   char *ipbuf = NULL;
    interface_info_t *intf;
 
    intf = (interface_info_t *) data;
    printf("Interface %d\n", intf->i);
    printf("   Name: %s\n", intf->name);
-   printf("   IPv4: %s\n", netlink_format_ip_addr(AF_INET, intf, ipbuf));
-   printf("   IPv6: %s\n", netlink_format_ip_addr(AF_INET6, intf, ipbuf));
+   if (intf->ip_addr.s_addr != 0)
+      printf("   IPv4: %s\n", netlink_format_ip_addr(AF_INET, intf, ipbuf));
+   else
+      printf("   IPv4: not set\n");
+   if (intf->ip6_addr.s6_addr[0] != 0)
+      printf("   IPv6: %s\n", netlink_format_ip_addr(AF_INET6, intf, ipbuf));
+   else
+      printf("   IPv6: not set\n");
    printf("    MAC: %s\n\n", netlink_format_mac_addr(buf, intf->mac));
 
    printf("   mac2str test for %s: |%s|\n", intf->name, netlink_interfaces_mac2str(intf->name));
+   printf("    ip2str test for %s: |%s|\n", intf->name, netlink_interfaces_ip2str(intf->name));
 
    printf("----------------------------------------------------------------\n");