[Libvirt-cim] [PATCH 3 of 4] FilterEntry: Support for mask in CIDR notation

[Chip Vincent]

+1.

On 10/06/2011 11:46 AM, Eduardo Lima (Etrunko) wrote:
>   src/Virt_FilterEntry.c |  88 ++++++++++++++++++++++++++++++++++++++++++-------
>   1 files changed, 74 insertions(+), 14 deletions(-)
>
>
> # HG changeset patch
> # User Eduardo Lima (Etrunko)<eblima at br.ibm.com>
> # Date 1317914740 10800
> # Node ID 1a08d8186f3064dfb0c38ecb5846ffc1e7d5de4d
> # Parent  a323895be993b3807cc41348ba3b74c76fb42596
> FilterEntry: Support for mask in CIDR notation
>
> The values for mask fields may have been written using the CIDR notation[1].
> For instance, take the libvirt 'no-ip-multicast' builtin filter:
>
> <filter name='no-ip-multicast' chain='ipv4'>
>    <uuid>47756f11-6057-1448-2cce-fda40fa23ba4</uuid>
>    <rule action='drop' direction='out' priority='500'>
>      <ip dstipaddr='224.0.0.0' dstipmask='4'/>
>    </rule>
> </filter>
>
> As libvirt-cim expects an address like string, for the mask, in this case the
> conversion will fail and will output an array with only zero values [0,0,0,0],
> when it actually should be [240,0,0,0].
>
> [1] http://en.wikipedia.org/wiki/Classless_Inter-Domain_Routing
>
> Signed-off-by: Eduardo Lima (Etrunko)<eblima at br.ibm.com>
>
> diff --git a/src/Virt_FilterEntry.c b/src/Virt_FilterEntry.c
> --- a/src/Virt_FilterEntry.c
> +++ b/src/Virt_FilterEntry.c
> @@ -115,6 +115,44 @@
>           return array;
>   }
>
> +static char *cidr_to_str(const char *cidr)
> +{
> +        char *ret = NULL;
> +        int val;
> +        unsigned int o1, o2, o3, o4;
> +
> +        if (cidr == NULL || strlen(cidr) == 0)
> +                return NULL;
> +
> +        CU_DEBUG("Enter %s(%s)", __FUNCTION__, cidr);
> +
> +        /* String value to integer */
> +        val = atoi(cidr);
> +        if (val<  0 || val>  32)
> +                return NULL;
> +
> +        if (val == 0)
> +                return strdup("0.0.0.0");
> +        else if (val == 32)
> +                return strdup("255.255.255.255");
> +
> +        /* CIDR to bits */
> +        val = (0xffffffff>>  (32 - val))<<  (32 - val);
> +
> +        /* bits to octets */
> +        o1 = (val&  0xff000000)>>  24;
> +        o2 = (val&  0x00ff0000)>>  16;
> +        o3 = (val&  0x0000ff00)>>  8;
> +        o4 = val&  0x000000ff;
> +
> +        /* octets to address string */
> +        ret = calloc(1, sizeof(*ret) * 16);
> +        snprintf(ret, 16, "%u.%u.%u.%u", o1, o2, o3, o4);
> +
> +        CU_DEBUG("%s: returning '%s'", __FUNCTION__, ret);
> +        return ret;
> +}
> +
>   static int convert_direction(const char *s)
>   {
>           enum {NOT_APPLICABLE, INPUT, OUTPUT, BOTH} direction = NOT_APPLICABLE;
> @@ -246,14 +284,25 @@
>                           CMSetProperty(inst, "HdrSrcAddress",
>                                   (CMPIValue *)&array, CMPI_uint8A);
>
> -                memset(bytes, 0, sizeof(bytes));
> -                size = octets_from_ip(rule->var.tcp.srcipmask,
> -                        bytes, sizeof(bytes));
> +                /* CIDR notation? */
> +                if (rule->var.tcp.srcipmask) {
> +                        char *netmask = strdup(rule->var.tcp.srcipmask);
> +                        if (strstr(netmask, ".") == NULL) {
> +                                char *tmp = cidr_to_str(netmask);
> +                                free(netmask);
> +                                netmask = tmp;
> +                        }
>
> -                array = octets_to_cmpi(broker, bytes, size);
> -                if (array != NULL)
> -                        CMSetProperty(inst, "HdrSrcMask",
> -                                (CMPIValue *)&array, CMPI_uint8A);
> +                        memset(bytes, 0, sizeof(bytes));
> +                        size = octets_from_ip(netmask, bytes, sizeof(bytes));
> +
> +                        array = octets_to_cmpi(broker, bytes, size);
> +                        if (array != NULL)
> +                                CMSetProperty(inst, "HdrSrcMask",
> +                                        (CMPIValue *)&array, CMPI_uint8A);
> +
> +                        free(netmask);
> +                }
>           }
>
>           if (rule->var.tcp.dstipfrom&&  rule->var.tcp.dstipto) {
> @@ -284,14 +333,25 @@
>                           CMSetProperty(inst, "HdrDestAddress",
>                                   (CMPIValue *)&array, CMPI_uint8A);
>
> -                memset(bytes, 0, sizeof(bytes));
> -                size = octets_from_ip(rule->var.tcp.dstipmask,
> -                        bytes, sizeof(bytes));
> +                /* CIDR notation? */
> +                if (rule->var.tcp.dstipmask) {
> +                        char *netmask = strdup(rule->var.tcp.dstipmask);
> +                        if (strstr(netmask, ".") == NULL) {
> +                                char *tmp = cidr_to_str(netmask);
> +                                free(netmask);
> +                                netmask = tmp;
> +                        }
>
> -                array = octets_to_cmpi(broker, bytes, size);
> -                if (array != NULL)
> -                        CMSetProperty(inst, "HdrDestMask",
> -                                (CMPIValue *)&array, CMPI_uint8A);
> +                        memset(bytes, 0, sizeof(bytes));
> +                        size = octets_from_ip(netmask, bytes, sizeof(bytes));
> +
> +                        array = octets_to_cmpi(broker, bytes, size);
> +                        if (array != NULL)
> +                                CMSetProperty(inst, "HdrDestMask",
> +                                        (CMPIValue *)&array, CMPI_uint8A);
> +
> +                        free(netmask);
> +                }
>           }
>
>           if ((rule->type == IP_RULE) || (rule->type == TCP_RULE)) {
>
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-- 
Chip Vincent
Open Virtualization
IBM Linux Technology Center
cvincent at linux.vnet.ibm.com