[ovs-dev,09/11] ofproto-dpif-slow: Add IPv6 agent address support.

Suggested-by: Neil McKee <neil.mckee@inmon.com>
Signed-off-by: Ben Pfaff <blp@ovn.org>
---
 ofproto/ofproto-dpif-sflow.c | 55 ++++++++++++++++++++++++++------------------
 1 file changed, 33 insertions(+), 22 deletions(-)

Looks ok to me.  Will this be accessible via ovs-vsctl?

If so, hsflowd will be able to tell ovs to use the same agent-address
as the one it already settled on.  Instead of just specifying the
device and hoping it works out:
https://github.com/sflow/host-sflow/blob/v2.0.15/src/Linux/mod_ovs.c#L258

So that's another use-case for this new option.


On Fri, Apr 13, 2018 at 10:26 AM, Ben Pfaff <blp@ovn.org> wrote:
> Suggested-by: Neil McKee <neil.mckee@inmon.com>
> Signed-off-by: Ben Pfaff <blp@ovn.org>
> ---
>  ofproto/ofproto-dpif-sflow.c | 55 ++++++++++++++++++++++++++------------------
>  1 file changed, 33 insertions(+), 22 deletions(-)
>
> diff --git a/ofproto/ofproto-dpif-sflow.c b/ofproto/ofproto-dpif-sflow.c
> index 5d8c0e19f8e3..fe79a9dbbad6 100644
> --- a/ofproto/ofproto-dpif-sflow.c
> +++ b/ofproto/ofproto-dpif-sflow.c
> @@ -446,43 +446,45 @@ sflow_choose_agent_address(const char *agent_device,
>                             const char *control_ip,
>                             SFLAddress *agent_addr)
>  {
> -    const char *target;
> -    struct in_addr in4;
> -
> -    memset(agent_addr, 0, sizeof *agent_addr);
> -    agent_addr->type = SFLADDRESSTYPE_IP_V4;
> +    struct in6_addr ip;
>
>      if (agent_device) {
> -        if (!netdev_get_in4_by_name(agent_device, &in4)
> -            || !lookup_ip(agent_device, &in4)) {
> +        /* If 'agent_device' is the name of a network device, use its IP
> +         * address. */
> +        if (!netdev_get_ip_by_name(agent_device, &ip)) {
> +            goto success;
> +        }
> +
> +        /* If 'agent_device' is itself an IP address, use it. */
> +        struct sockaddr_storage ss;
> +        if (inet_parse_address(agent_device, &ss)) {
> +            ip = ss_get_address(&ss);
>              goto success;
>          }
>      }
>
> +    /* Otherwise, use an appropriate local IP address for one of the
> +     * collectors' remote IP addresses. */
> +    const char *target;
>      SSET_FOR_EACH (target, targets) {
> -        union {
> -            struct sockaddr_storage ss;
> -            struct sockaddr_in sin;
> -        } sa;
> -        char name[IFNAMSIZ];
> -
> -        if (inet_parse_active(target, SFL_DEFAULT_COLLECTOR_PORT, &sa.ss)
> -            && sa.ss.ss_family == AF_INET) {
> -            struct in6_addr addr6, src, gw;
> -
> -            in6_addr_set_mapped_ipv4(&addr6, sa.sin.sin_addr.s_addr);
> +        struct sockaddr_storage ss;
> +        if (inet_parse_active(target, SFL_DEFAULT_COLLECTOR_PORT, &ss)) {
>              /* sFlow only supports target in default routing table with
>               * packet mark zero.
>               */
> -            if (ovs_router_lookup(0, &addr6, name, &src, &gw)) {
> +            ip = ss_get_address(&ss);
>
> -                in4.s_addr = in6_addr_get_mapped_ipv4(&src);
> +            struct in6_addr src, gw;
> +            char name[IFNAMSIZ];
> +            if (ovs_router_lookup(0, &ip, name, &src, &gw)) {
>                  goto success;
>              }
>          }
>      }
>
> -    if (control_ip && !lookup_ip(control_ip, &in4)) {
> +    struct sockaddr_storage ss;
> +    if (control_ip && inet_parse_address(control_ip, &ss)) {
> +        ip = ss_get_address(&ss);
>          goto success;
>      }
>
> @@ -490,7 +492,16 @@ sflow_choose_agent_address(const char *agent_device,
>      return false;
>
>  success:
> -    agent_addr->address.ip_v4.addr = (OVS_FORCE uint32_t) in4.s_addr;
> +    memset(agent_addr, 0, sizeof *agent_addr);
> +    if (IN6_IS_ADDR_V4MAPPED(&ip)) {
> +        agent_addr->type = SFLADDRESSTYPE_IP_V4;
> +        agent_addr->address.ip_v4.addr
> +            = (OVS_FORCE uint32_t) in6_addr_get_mapped_ipv4(&ip);
> +    } else {
> +        agent_addr->type = SFLADDRESSTYPE_IP_V6;
> +        memcpy(agent_addr->address.ip_v6.addr, ip.s6_addr,
> +               sizeof agent_addr->address.ip_v6.addr);
> +    }
>      return true;
>  }
>
> --
> 2.16.1
>

Thanks for taking a look!

On Fri, Apr 13, 2018 at 12:27:40PM -0700, Neil McKee wrote:
> Looks ok to me.  Will this be accessible via ovs-vsctl?

Yes, it should work the same as before.

> If so, hsflowd will be able to tell ovs to use the same agent-address
> as the one it already settled on.  Instead of just specifying the
> device and hoping it works out:
> https://github.com/sflow/host-sflow/blob/v2.0.15/src/Linux/mod_ovs.c#L258
> 
> So that's another use-case for this new option.

Even better, great.