qga: add network stats to guest-network-get-interfaces

we can get the network interface statistics inside a virtual machine by
guest-network-get-interfaces command. it is very useful for us tomonitor
and analyze network traffic.

Signed-off-by: ZhiPeng Lu <lu.zhipeng@zte.com.cn>
* don't rely on sizeof(wchar[]) for wchar[] indexing
* avoid camelCase variable names
* fix up getline() usage
* condensed commit subject line
Signed-off-by: Michael Roth <mdroth@linux.vnet.ibm.com>

1 files changed, 73 insertions, 1 deletions

diff --git a/qga/commands-posix.c b/qga/commands-posix.c
index ab0c63d931..e809e382eb 100644
--- a/qga/commands-posix.c
+++ b/qga/commands-posix.c
@@ -1643,6 +1643,67 @@ guest_find_interface(GuestNetworkInterfaceList *head,
     return head;
 }
 
+static int guest_get_network_stats(const char *name,
+                       GuestNetworkInterfaceStat *stats)
+{
+    int name_len;
+    char const *devinfo = "/proc/net/dev";
+    FILE *fp;
+    char *line = NULL, *colon;
+    size_t n = 0;
+    fp = fopen(devinfo, "r");
+    if (!fp) {
+        return -1;
+    }
+    name_len = strlen(name);
+    while (getline(&line, &n, fp) != -1) {
+        long long dummy;
+        long long rx_bytes;
+        long long rx_packets;
+        long long rx_errs;
+        long long rx_dropped;
+        long long tx_bytes;
+        long long tx_packets;
+        long long tx_errs;
+        long long tx_dropped;
+        char *trim_line;
+        trim_line = g_strchug(line);
+        if (trim_line[0] == '\0') {
+            continue;
+        }
+        colon = strchr(trim_line, ':');
+        if (!colon) {
+            continue;
+        }
+        if (colon - name_len  == trim_line &&
+           strncmp(trim_line, name, name_len) == 0) {
+            if (sscanf(colon + 1,
+                "%lld %lld %lld %lld %lld %lld %lld %lld %lld %lld %lld %lld %lld %lld %lld %lld",
+                  &rx_bytes, &rx_packets, &rx_errs, &rx_dropped,
+                  &dummy, &dummy, &dummy, &dummy,
+                  &tx_bytes, &tx_packets, &tx_errs, &tx_dropped,
+                  &dummy, &dummy, &dummy, &dummy) != 16) {
+                continue;
+            }
+            stats->rx_bytes = rx_bytes;
+            stats->rx_packets = rx_packets;
+            stats->rx_errs = rx_errs;
+            stats->rx_dropped = rx_dropped;
+            stats->tx_bytes = tx_bytes;
+            stats->tx_packets = tx_packets;
+            stats->tx_errs = tx_errs;
+            stats->tx_dropped = tx_dropped;
+            fclose(fp);
+            g_free(line);
+            return 0;
+        }
+    }
+    fclose(fp);
+    g_free(line);
+    g_debug("/proc/net/dev: Interface '%s' not found", name);
+    return -1;
+}
+
 /*
  * Build information about guest interfaces
  */
@@ -1659,6 +1720,7 @@ GuestNetworkInterfaceList *qmp_guest_network_get_interfaces(Error **errp)
     for (ifa = ifap; ifa; ifa = ifa->ifa_next) {
         GuestNetworkInterfaceList *info;
         GuestIpAddressList **address_list = NULL, *address_item = NULL;
+        GuestNetworkInterfaceStat  *interface_stat = NULL;
         char addr4[INET_ADDRSTRLEN];
         char addr6[INET6_ADDRSTRLEN];
         int sock;
@@ -1778,7 +1840,17 @@ GuestNetworkInterfaceList *qmp_guest_network_get_interfaces(Error **errp)
 
         info->value->has_ip_addresses = true;
 
-
+        if (!info->value->has_statistics) {
+            interface_stat = g_malloc0(sizeof(*interface_stat));
+            if (guest_get_network_stats(info->value->name,
+                interface_stat) == -1) {
+                info->value->has_statistics = false;
+                g_free(interface_stat);
+            } else {
+                info->value->statistics = interface_stat;
+                info->value->has_statistics = true;
+            }
+        }
     }
 
     freeifaddrs(ifap);