[ovs-dev] [PATCH 4/7] dpif-netlink-rtnl: add VXLAN creation support

[Joe Stringer]

On 16 March 2017 at 13:22, Eric Garver <e at erig.me> wrote:
> Creates VXLAN devices using rtnetlink and tunnel metadata.
>
> Co-Authored-by: Thadeu Lima de Souza Cascardo <cascardo at redhat.com>
> Signed-off-by: Thadeu Lima de Souza Cascardo <cascardo at redhat.com>
> Signed-off-by: Eric Garver <e at erig.me>
> ---
>  lib/dpif-netlink-rtnl.c | 175 +++++++++++++++++++++++++++++++++++++++++++++++-
>  lib/dpif-netlink-rtnl.h |   3 +-
>  2 files changed, 175 insertions(+), 3 deletions(-)
>
> diff --git a/lib/dpif-netlink-rtnl.c b/lib/dpif-netlink-rtnl.c
> index 1f816feee569..c07d7df8d13a 100644
> --- a/lib/dpif-netlink-rtnl.c
> +++ b/lib/dpif-netlink-rtnl.c
> @@ -17,14 +17,186 @@
>  #include <config.h>
>
>  #include "dpif-netlink-rtnl.h"
> +
> +#include <net/if.h>
> +#include <linux/ip.h>
> +#include <linux/rtnetlink.h>
> +
>  #include "dpif-netlink.h"
> +#include "netdev-vport.h"
> +#include "netlink-socket.h"
> +
> +/*
> + * On some older systems, these enums are not defined.
> + */
> +#ifndef IFLA_VXLAN_MAX
> +#define IFLA_VXLAN_MAX 0
> +#endif
> +#if IFLA_VXLAN_MAX < 25
> +#define IFLA_VXLAN_LEARNING 7
> +#define IFLA_VXLAN_PORT 15
> +#define IFLA_VXLAN_UDP_ZERO_CSUM6_RX 20
> +#define IFLA_VXLAN_GBP 23
> +#define IFLA_VXLAN_COLLECT_METADATA 25
> +#endif
> +
> +static const struct nl_policy rtlink_policy[] = {
> +    [IFLA_LINKINFO] = { .type = NL_A_NESTED },
> +};
> +static const struct nl_policy linkinfo_policy[] = {
> +    [IFLA_INFO_KIND] = { .type = NL_A_STRING },
> +    [IFLA_INFO_DATA] = { .type = NL_A_NESTED },
> +};
> +
> +
> +static int
> +dpif_netlink_rtnl_destroy(const char *name)
> +{
> +    int err;
> +    struct ofpbuf request;
> +
> +    ofpbuf_init(&request, 0);
> +    nl_msg_put_nlmsghdr(&request, 0, RTM_DELLINK, NLM_F_REQUEST | NLM_F_ACK);
> +    ofpbuf_put_zeros(&request, sizeof(struct ifinfomsg));
> +    nl_msg_put_string(&request, IFLA_IFNAME, name);
> +
> +    err = nl_transact(NETLINK_ROUTE, &request, NULL);
> +    ofpbuf_uninit(&request);
> +
> +    return err;
> +}
> +
> +static int
> +dpif_netlink_rtnl_vxlan_destroy(const char *name)
> +{
> +    return dpif_netlink_rtnl_destroy(name);
> +}
> +
> +static int
> +dpif_netlink_rtnl_vxlan_verify(struct netdev *netdev, const char *name,
> +                               const char *kind)
> +{
> +    int err;
> +    struct ofpbuf request, *reply;
> +    struct ifinfomsg *ifmsg;
> +    const struct netdev_tunnel_config *tnl_cfg;
> +
> +    static const struct nl_policy vxlan_policy[] = {
> +        [IFLA_VXLAN_COLLECT_METADATA] = { .type = NL_A_U8 },
> +        [IFLA_VXLAN_LEARNING] = { .type = NL_A_U8 },
> +        [IFLA_VXLAN_UDP_ZERO_CSUM6_RX] = { .type = NL_A_U8 },
> +        [IFLA_VXLAN_PORT] = { .type = NL_A_U16 },
> +    };
> +
> +    tnl_cfg = netdev_get_tunnel_config(netdev);
> +    if (!tnl_cfg) {
> +        return EINVAL;
> +    }
>
> +    ofpbuf_init(&request, 0);
> +    nl_msg_put_nlmsghdr(&request, 0, RTM_GETLINK, NLM_F_REQUEST);
> +    ofpbuf_put_zeros(&request, sizeof(struct ifinfomsg));
> +    nl_msg_put_string(&request, IFLA_IFNAME, name);
> +
> +    err = nl_transact(NETLINK_ROUTE, &request, &reply);
> +    ofpbuf_uninit(&request);

Could this snippet between the ofpbuf_init() and ofpbuf_uninit() be
refactored and reused by all the tunnel types?

> +
> +    if (!err) {
> +        struct nlattr *rtlink[ARRAY_SIZE(rtlink_policy)];
> +        struct nlattr *linkinfo[ARRAY_SIZE(linkinfo_policy)];
> +        struct nlattr *vxlan[ARRAY_SIZE(vxlan_policy)];
> +
> +        ifmsg = ofpbuf_at(reply, NLMSG_HDRLEN, sizeof *ifmsg);
> +        if (!nl_policy_parse(reply, NLMSG_HDRLEN + sizeof *ifmsg,
> +                             rtlink_policy, rtlink, ARRAY_SIZE(rtlink_policy))
> +            || !nl_parse_nested(rtlink[IFLA_LINKINFO], linkinfo_policy,
> +                                linkinfo, ARRAY_SIZE(linkinfo_policy))
> +            || strcmp(nl_attr_get_string(linkinfo[IFLA_INFO_KIND]), kind)
> +            || !nl_parse_nested(linkinfo[IFLA_INFO_DATA], vxlan_policy, vxlan,
> +                                ARRAY_SIZE(vxlan_policy))) {
> +            err = EINVAL;
> +        }
> +        if (!err) {
> +            if (0 != nl_attr_get_u8(vxlan[IFLA_VXLAN_LEARNING])
> +                || 1 != nl_attr_get_u8(vxlan[IFLA_VXLAN_COLLECT_METADATA])
> +                || 1 != nl_attr_get_u8(vxlan[IFLA_VXLAN_UDP_ZERO_CSUM6_RX])
> +                || (tnl_cfg->dst_port !=
> +                    nl_attr_get_be16(vxlan[IFLA_VXLAN_PORT]))) {
> +                err = EINVAL;
> +            }
> +        }
> +        if (!err) {
> +            if (tnl_cfg->exts & (1 << OVS_VXLAN_EXT_GBP)
> +                && !nl_attr_get_flag(vxlan[IFLA_VXLAN_GBP])) {
> +                err = EINVAL;
> +            }
> +        }
> +        ofpbuf_delete(reply);
> +    }
> +
> +    return err;
> +}
> +
> +static int
> +dpif_netlink_rtnl_vxlan_create_kind(struct netdev *netdev, const char *kind)
> +{
> +    int err;
> +    struct ofpbuf request;
> +    size_t linkinfo_off, infodata_off;
> +    char namebuf[NETDEV_VPORT_NAME_BUFSIZE];
> +    const char *name = netdev_vport_get_dpif_port(netdev,
> +                                                  namebuf, sizeof namebuf);
> +    struct ifinfomsg *ifinfo;
> +    const struct netdev_tunnel_config *tnl_cfg;

Minor thing, but if you'll respin anyway... we usually use the other
christmas tree (long lines to small lines) and place a space after the
variables declarations at the beginning of functions. This applies to
several locations in the series.