[PATCH 09/17] Tools: hv: Represent the ipv6 mask using CIDR notation

K. Y. Srinivasan
2012-07-24T15:47:12Z

Transform ipv6 subnet information to CIDR notation.

Signed-off-by: K. Y. Srinivasan <kys@microsoft.com>
Reviewed-by: Haiyang Zhang <haiyangz@microsoft.com>
---
tools/hv/hv_kvp_daemon.c | 45 +++++++++++++++++++++++++++++++++++----------
1 files changed, 35 insertions(+), 10 deletions(-)

diff --git a/tools/hv/hv_kvp_daemon.c b/tools/hv/hv_kvp_daemon.c
index 2c24ebf..007e698 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;
@@ -612,17 +626,28 @@ kvp_get_ip_address(int family, char *if_name, int op,
} 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;
}
}

--
1.7.4.1