net-dhcp-leases: Add virsh support

Use virNetworkGetDHCPLeases and virNetworkGetDHCPLeasesForMAC in virsh.

The new feature supports the follwing methods:

1. Retrieve leases info for a given virtual network

2. Retrieve leases info for given network interface

tools/virsh-domain-monitor.c
   * Introduce new command : net-dhcp-leases
     Example Usage: net-dhcp-leases <network> [mac]

   virsh # net-dhcp-leases --network default6
   Expiry Time          MAC address        Protocol  IP address                Hostname        Client ID or DUID
   -------------------------------------------------------------------------------------------------------------------
   2014-06-16 03:40:14  52:54:00:85:90:e2  ipv4      192.168.150.231/24        fedora20-test   01:52:54:00:85:90:e2
   2014-06-16 03:40:17  52:54:00:85:90:e2  ipv6      2001:db8:ca2:2:1::c0/64   fedora20-test   00:04:b1:d8:86:42:e1:6a:aa:cf:d5:86:94:23:6f:94:04:cd
   2014-06-16 03:34:42  52:54:00:e8:73:eb  ipv4      192.168.150.181/24        ubuntu14-vm     -
   2014-06-16 03:34:46  52:54:00:e8:73:eb  ipv6      2001:db8:ca2:2:1::5b/64   -               00:01:00:01:1b:30:c6:aa:52:54:00:e8:73:eb

tools/virsh.pod
   * Document new command

src/internal.h
   * Introduce new macro: EMPTYSTR

src/internal.h

@@ -246,6 +246,11 @@
  */
 # define NULLSTR(s) ((s) ? (s) : "<null>")
 
+/*
+ * Similar to NULLSTR, but print '-' to make it more user friendly.
+ */
+# define EMPTYSTR(s) ((s) ? (s) : "-")
+
 /**
  * TODO:
  *

tools/virsh-network.c

@@ -1285,6 +1285,119 @@ cmdNetworkEvent(vshControl *ctl, const vshCmd *cmd)
 }
 
 
+/*
+ * "net-dhcp-leases" command
+ */
+static const vshCmdInfo info_network_dhcp_leases[] = {
+    {.name = "help",
+     .data = N_("print lease info for a given network")
+    },
+    {.name = "desc",
+     .data = N_("Print lease info for a given network")
+    },
+    {.name = NULL}
+};
+
+static const vshCmdOptDef opts_network_dhcp_leases[] = {
+    {.name = "network",
+     .type = VSH_OT_DATA,
+     .flags = VSH_OFLAG_REQ,
+     .help = N_("network name or uuid")
+    },
+    {.name = "mac",
+     .type = VSH_OT_DATA,
+     .flags = VSH_OFLAG_NONE,
+     .help = N_("MAC address")
+    },
+    {.name = NULL}
+};
+
+static int
+vshNetworkDHCPLeaseSorter(const void *a, const void *b)
+{
+    int rv = -1;
+
+    virNetworkDHCPLeasePtr *lease1 = (virNetworkDHCPLeasePtr *) a;
+    virNetworkDHCPLeasePtr *lease2 = (virNetworkDHCPLeasePtr *) b;
+
+    if (*lease1 && !*lease2)
+        return -1;
+
+    if (!*lease1)
+        return *lease2 != NULL;
+
+    rv = vshStrcasecmp((*lease1)->mac, (*lease2)->mac);
+    return rv;
+}
+
+static bool
+cmdNetworkDHCPLeases(vshControl *ctl, const vshCmd *cmd)
+{
+    const char *name = NULL;
+    const char *mac = NULL;
+    virNetworkDHCPLeasePtr *leases = NULL;
+    int nleases = 0;
+    bool ret = false;
+    size_t i;
+    unsigned int flags = 0;
+    virNetworkPtr network = NULL;
+
+    if (vshCommandOptString(cmd, "mac", &mac) < 0)
+        return false;
+
+    if (!(network = vshCommandOptNetwork(ctl, cmd, &name)))
+        return false;
+
+    nleases = mac ? virNetworkGetDHCPLeasesForMAC(network, mac, &leases, flags)
+        : virNetworkGetDHCPLeases(network, &leases, flags);
+
+    if (nleases < 0) {
+        vshError(ctl, _("Failed to get leases info for %s"), name);
+        goto cleanup;
+    }
+
+    /* Sort the list according to MAC Address/IAID */
+    qsort(leases, nleases, sizeof(*leases), vshNetworkDHCPLeaseSorter);
+
+    vshPrintExtra(ctl, " %-20s %-18s %-9s %-25s %-15s %s\n%s%s\n",
+                  _("Expiry Time"), _("MAC address"), _("Protocol"),
+                  _("IP address"), _("Hostname"), _("Client ID or DUID"),
+                  "----------------------------------------------------------",
+                  "---------------------------------------------------------");
+
+    for (i = 0; i < nleases; i++) {
+        const char *type = NULL;
+        char *cidr_format = NULL;
+        virNetworkDHCPLeasePtr lease = leases[i];
+        time_t expirytime_tmp = lease->expirytime;
+        struct tm ts;
+        char expirytime[32];
+        ts = *localtime_r(&expirytime_tmp, &ts);
+        strftime(expirytime, sizeof(expirytime), "%Y-%m-%d %H:%M:%S", &ts);
+
+        type = (lease->type == VIR_IP_ADDR_TYPE_IPV4) ? "ipv4" :
+            (lease->type == VIR_IP_ADDR_TYPE_IPV6) ? "ipv6" : "";
+
+        ignore_value(virAsprintf(&cidr_format, "%s/%d",
+                                 lease->ipaddr, lease->prefix));
+
+        vshPrintExtra(ctl, " %-20s %-18s %-9s %-25s %-15s %s\n",
+                      expirytime, EMPTYSTR(lease->mac), EMPTYSTR(type), cidr_format,
+                      EMPTYSTR(lease->hostname), EMPTYSTR(lease->clientid));
+    }
+
+    ret = true;
+
+ cleanup:
+    if (leases) {
+        for (i = 0; i < nleases; i++)
+            virNetworkDHCPLeaseFree(leases[i]);
+        VIR_FREE(leases);
+    }
+    virNetworkFree(network);
+    return ret;
+}
+
 const vshCmdDef networkCmds[] = {
     {.name = "net-autostart",
      .handler = cmdNetworkAutostart,
@@ -1310,6 +1423,12 @@ const vshCmdDef networkCmds[] = {
      .info = info_network_destroy,
      .flags = 0
     },
+    {.name = "net-dhcp-leases",
+     .handler = cmdNetworkDHCPLeases,
+     .opts = opts_network_dhcp_leases,
+     .info = info_network_dhcp_leases,
+     .flags = 0,
+    },
     {.name = "net-dumpxml",
      .handler = cmdNetworkDumpXML,
      .opts = opts_network_dumpxml,

tools/virsh.pod

@@ -2525,6 +2525,12 @@ If I<--current> is specified, affect the current network state.
 Both I<--live> and I<--config> flags may be given, but I<--current> is
 exclusive. Not specifying any flag is the same as specifying I<--current>.
 
+=item B<net-dhcp-leases> I<network> [I<mac>]
+
+Get a list of dhcp leases for all network interfaces connected to the given
+virtual I<network> or limited output just for one interface if I<mac> is
+specified.
+
 =back
 
 =head1 INTERFACE COMMANDS