[Qemu-devel] [PATCH] qemu-ga: Extend guest-network-get-interfaces

[Michal Privoznik]

Nowadays only basic information is reported. However, with the
current implementation much more can be exposed to users. like
broadcast/destination address (the former in case of standard
ethernet device, the latter in case of PPP interface), if the
interface is up, of type loopback, in promisc mode or capable of
sending multicast.
---

Based on getifaddrs manpage, interface can either has a PTP peer,
or a broadcast. While it can has up to one peer address, it can
has multiple broadcast addresses. Therefore the broadcast address
needs to be within GuestIpAddress.

 qga/commands-posix.c | 65 ++++++++++++++++++++++++++++++++++++++++++++++++++++
 qga/qapi-schema.json | 37 +++++++++++++++++++++++++++---
 2 files changed, 99 insertions(+), 3 deletions(-)

diff --git a/qga/commands-posix.c b/qga/commands-posix.c
index a657201..7717fbf 100644
--- a/qga/commands-posix.c
+++ b/qga/commands-posix.c
@@ -816,6 +816,11 @@ GuestNetworkInterfaceList 
*qmp_guest_network_get_interfaces(Error **errp)
             }
         }
 
+        info->value->up = ifa->ifa_flags & IFF_UP;
+        info->value->loopback = ifa->ifa_flags & IFF_LOOPBACK;
+        info->value->promisc = ifa->ifa_flags & IFF_PROMISC;
+        info->value->multicast = ifa->ifa_flags & IFF_MULTICAST;
+
         if (!info->value->has_hardware_address &&
             ifa->ifa_flags & SIOCGIFHWADDR) {
             /* we haven't obtained HW address yet */
@@ -909,6 +914,66 @@ GuestNetworkInterfaceList 
*qmp_guest_network_get_interfaces(Error **errp)
             continue;
         }
 
+        if (ifa->ifa_broadaddr &&
+            ifa->ifa_flags & IFF_BROADCAST) {
+            /* interface has a broadcast address set */
+            info->value->has_type = true;
+            info->value->type = GUEST_NETWORK_INTERFACE_TYPE_BROADCAST;
+
+            if (ifa->ifa_addr->sa_family == AF_INET) {
+                /* and the broadcast is an IPv4 address */
+                p = &((struct sockaddr_in *)ifa->ifa_broadaddr)->sin_addr;
+                if (!inet_ntop(AF_INET, p, addr4, sizeof(addr4))) {
+                    snprintf(err_msg, sizeof(err_msg),
+                             "inet_ntop failed : %s", strerror(errno));
+                    error_set(errp, QERR_QGA_COMMAND_FAILED, err_msg);
+                    goto error;
+                }
+                address_item->value->dest_address = g_strdup(addr4);
+                address_item->value->has_dest_address = true;
+            } else {
+                /* or it is an IPv6 address */
+                p = &((struct sockaddr_in6 *)ifa->ifa_broadaddr)->sin6_addr;
+                if (!inet_ntop(AF_INET6, p, addr6, sizeof(addr6))) {
+                    snprintf(err_msg, sizeof(err_msg),
+                             "inet_ntop failed : %s", strerror(errno));
+                    error_set(errp, QERR_QGA_COMMAND_FAILED, err_msg);
+                    goto error;
+                }
+                address_item->value->dest_address = g_strdup(addr6);
+                address_item->value->has_dest_address = true;
+            }
+        } else if (ifa->ifa_dstaddr &&
+                   ifa->ifa_flags & IFF_POINTOPOINT) {
+            /* interface is point to point */
+            info->value->has_type = true;
+            info->value->type = GUEST_NETWORK_INTERFACE_TYPE_PPP;
+
+            if (ifa->ifa_addr->sa_family == AF_INET) {
+                /* and the peer has an IPv4 address */
+                p = &((struct sockaddr_in *)ifa->ifa_dstaddr)->sin_addr;
+                if (!inet_ntop(AF_INET, p, addr4, sizeof(addr4))) {
+                    snprintf(err_msg, sizeof(err_msg),
+                             "inet_ntop failed : %s", strerror(errno));
+                    error_set(errp, QERR_QGA_COMMAND_FAILED, err_msg);
+                    goto error;
+                }
+                address_item->value->dest_address = g_strdup(addr4);
+                address_item->value->has_dest_address = true;
+            } else {
+                /* or it has an IPv6 address */
+                p = &((struct sockaddr_in6 *)ifa->ifa_dstaddr)->sin6_addr;
+                if (!inet_ntop(AF_INET6, p, addr6, sizeof(addr6))) {
+                    snprintf(err_msg, sizeof(err_msg),
+                             "inet_ntop failed : %s", strerror(errno));
+                    error_set(errp, QERR_QGA_COMMAND_FAILED, err_msg);
+                    goto error;
+                }
+                address_item->value->dest_address = g_strdup(addr6);
+                address_item->value->has_dest_address = true;
+            }
+        }
+
         address_list = &info->value->ip_addresses;
 
         while (*address_list && (*address_list)->next) {
diff --git a/qga/qapi-schema.json b/qga/qapi-schema.json
index ed0eb69..066e6aa 100644
--- a/qga/qapi-schema.json
+++ b/qga/qapi-schema.json
@@ -480,26 +480,57 @@
 #
 # @prefix: Network prefix length of @ip-address
 #
-# Since: 1.1
+# @dest-address: The broadcast or peer address.
+#
+# Since: 1.1, @dest-address since 1.3
 ##
 { 'type': 'GuestIpAddress',
   'data': {'ip-address': 'str',
            'ip-address-type': 'GuestIpAddressType',
-           'prefix': 'int'} }
+           'prefix': 'int',
+           '*dest-address': 'str'} }
 
 ##
+# @GuestNetworkInterfaceType:
+#
+# @broadcast: Interface has a broadcast address. In which case it is
+#             contained in @dest-address in @GuestIpAddress.
+#
+# @ppp: Interface is of point-to-point type. The peer address is then in
+#       @dest-address in @GuestIpAddress.
+#
+# Since: 1.3
+##
+{ 'enum': 'GuestNetworkInterfaceType',
+  'data': ['broadcast', 'ppp'] }
+##
 # @GuestNetworkInterface:
 #
 # @name: The name of interface for which info are being delivered
 #
+# @up: If the interface is up
+#
+# @loopback: If the interface is of loopback type
+#
+# @promisc: If the interface is in promiscuous mode
+#
+# @multicast: If the interface is cappable of multicast
+#
+# @type: If the interface has a broadcast address(-es) assigned, or is a PPP.
+#
 # @hardware-address: Hardware address of @name
 #
 # @ip-addresses: List of addresses assigned to @name
 #
-# Since: 1.1
+# Since: 1.1, @up, @loopback, @promisc, @multicast and @type since 1.3
 ##
 { 'type': 'GuestNetworkInterface',
   'data': {'name': 'str',
+           'up': 'bool',
+           'loopback': 'bool',
+           'promisc': 'bool',
+           'multicast': 'bool',
+           '*type': 'GuestNetworkInterfaceType',
            '*hardware-address': 'str',
            '*ip-addresses': ['GuestIpAddress'] } }
 
-- 
1.8.0.2