Tools: hv: Represent the ipv6 mask using CIDR notation

Transform ipv6 subnet information to CIDR notation.

Signed-off-by: K. Y. Srinivasan <kys@microsoft.com>
Reviewed-by: Haiyang Zhang <haiyangz@microsoft.com>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>

1 files changed, 36 insertions, 10 deletions

diff --git a/tools/hv/hv_kvp_daemon.c b/tools/hv/hv_kvp_daemon.c
index de1724cbaf5..a63e83a0159 100644
--- a/tools/hv/hv_kvp_daemon.c
+++ b/tools/hv/hv_kvp_daemon.c
@@ -491,6 +491,15 @@ done:
         return;
 }
 
+static unsigned int hweight32(unsigned int *w)
+{
+        unsigned int res = *w - ((*w >> 1) & 0x55555555);
+        res = (res & 0x33333333) + ((res >> 2) & 0x33333333);
+        res = (res + (res >> 4)) & 0x0F0F0F0F;
+        res = res + (res >> 8);
+        return (res + (res >> 16)) & 0x000000FF;
+}
+
 static int kvp_process_ip_address(void *addrp,
                                 int family, char *buffer,
                                 int length,  int *offset)
@@ -535,10 +544,15 @@ kvp_get_ip_address(int family, char *if_name, int op,
         struct ifaddrs *curp;
         int offset = 0;
         int sn_offset = 0;
-        const char *str;
         int error = 0;
         char *buffer;
         struct hv_kvp_ipaddr_value *ip_buffer;
+        char cidr_mask[5]; /* /xyz */
+        int weight;
+        int i;
+        unsigned int *w;
+        char *sn_str;
+        struct sockaddr_in6 *addr6;
 
         if (op == KVP_OP_ENUMERATE) {
                 buffer = out_buffer;
@@ -611,18 +625,30 @@ kvp_get_ip_address(int family, char *if_name, int op,
                                         goto gather_ipaddr;
                         } else {
                                 ip_buffer->addr_family |= ADDR_FAMILY_IPV6;
+
                                 /*
-                                 * Get subnet info.
+                                 * Get subnet info in CIDR format.
                                  */
-                                error = kvp_process_ip_address(
-                                                             curp->ifa_netmask,
-                                                             AF_INET6,
-                                                             (char *)
-                                                             ip_buffer->sub_net,
-                                                             length,
-                                                             &sn_offset);
-                                if (error)
+                                weight = 0;
+                                sn_str = (char *)ip_buffer->sub_net;
+                                addr6 = (struct sockaddr_in6 *)
+                                        curp->ifa_netmask;
+                                w = addr6->sin6_addr.s6_addr32;
+
+                                for (i = 0; i < 4; i++)
+                                        weight += hweight32(&w[i]);
+
+                                sprintf(cidr_mask, "/%d", weight);
+                                if ((length - sn_offset) <
+                                        (strlen(cidr_mask) + 1))
                                         goto gather_ipaddr;
+
+                                if (sn_offset == 0)
+                                        strcpy(sn_str, cidr_mask);
+                                else
+                                        strcat(sn_str, cidr_mask);
+                                strcat((char *)ip_buffer->sub_net, ";");
+                                sn_offset += strlen(sn_str) + 1;
                         }
                 }