On Tue, Jul 07, 2020 at 02:24:29PM -0700, Jakub Kicinski wrote:
> Add an interface to report offloaded UDP ports via ethtool netlink.
>
> Now that core takes care of tracking which UDP tunnel ports the NICs
> are aware of we can quite easily export this information out to
> user space.
>
> The responsibility of writing the netlink dumps is split between
> ethtool code and udp_tunnel_nic.c - since udp_tunnel module may
> not always be loaded, yet we should always report the capabilities
> of the NIC.
>
> $ ethtool --show-tunnels eth0
> Tunnel information for eth0:
> UDP port table 0:
> Size: 4
> Types: vxlan
> No entries
> UDP port table 1:
> Size: 4
> Types: geneve, vxlan-gpe
> Entries (1):
> port 1230, vxlan-gpe
>
> Signed-off-by: Jakub Kicinski <k...@kernel.org>
> ---
> Documentation/networking/ethtool-netlink.rst | 33 +++
> include/net/udp_tunnel.h | 21 ++
> include/uapi/linux/ethtool.h | 2 +
> include/uapi/linux/ethtool_netlink.h | 55 ++++
> net/ethtool/Makefile | 3 +-
> net/ethtool/common.c | 9 +
> net/ethtool/common.h | 1 +
> net/ethtool/netlink.c | 12 +
> net/ethtool/netlink.h | 4 +
> net/ethtool/strset.c | 5 +
> net/ethtool/tunnels.c | 261 +++++++++++++++++++
> net/ipv4/udp_tunnel_nic.c | 69 +++++
> 12 files changed, 474 insertions(+), 1 deletion(-)
> create mode 100644 net/ethtool/tunnels.c
>
> diff --git a/Documentation/networking/ethtool-netlink.rst
> b/Documentation/networking/ethtool-netlink.rst
> index 396390f4936b..6a9265401d31 100644
> --- a/Documentation/networking/ethtool-netlink.rst
> +++ b/Documentation/networking/ethtool-netlink.rst
> @@ -1230,6 +1230,39 @@ used to report the amplitude of the reflection for a
> given pair.
> | | | ``ETHTOOL_A_CABLE_AMPLITUDE_mV`` | s16 | Reflection
> amplitude |
>
> +-+-+-----------------------------------------+--------+----------------------+
>
> +TUNNEL_INFO
> +===========
> +
> +Gets information about the tunnel state NIC is aware of.
> +
> +Request contents:
> +
> + ===================================== ====== ==========================
> + ``ETHTOOL_A_TUNNEL_INFO_HEADER`` nested request header
> + ===================================== ====== ==========================
> +
> +Kernel response contents:
> +
> +
> +---------------------------------------------+--------+---------------------+
> + | ``ETHTOOL_A_TUNNEL_INFO_HEADER`` | nested | reply header
> |
> +
> +---------------------------------------------+--------+---------------------+
> + | ``ETHTOOL_A_TUNNEL_INFO_UDP_PORTS`` | nested | all UDP port
> tables |
> +
> +-+-------------------------------------------+--------+---------------------+
> + | | ``ETHTOOL_A_TUNNEL_UDP_TABLE`` | nested | one UDP port table
> |
> +
> +-+-+-----------------------------------------+--------+---------------------+
> + | | | ``ETHTOOL_A_TUNNEL_UDP_TABLE_SIZE`` | u32 | max size of the
> |
> + | | | | | table
> |
> +
> +-+-+-----------------------------------------+--------+---------------------+
> + | | | ``ETHTOOL_A_TUNNEL_UDP_TABLE_TYPES`` | u32 | bitmask of tunnel
> |
> + | | | | | types table can
> hold|
In the code below, this is a bitset, not u32.
> +
> +-+-+-----------------------------------------+--------+---------------------+
> + | | | ``ETHTOOL_A_TUNNEL_UDP_TABLE_ENTRY`` | nested | offloaded UDP port
> |
> +
> +-+-+-+---------------------------------------+--------+---------------------+
> + | | | | ``ETHTOOL_A_TUNNEL_UDP_ENTRY_PORT`` | be16 | UDP port
> |
> +
> +-+-+-+---------------------------------------+--------+---------------------+
> + | | | | ``ETHTOOL_A_TUNNEL_UDP_ENTRY_TYPE`` | u32 | tunnel type
> |
> +
> +-+-+-+---------------------------------------+--------+---------------------+
> +
> Request translation
> ===================
>
[...]
> diff --git a/include/uapi/linux/ethtool.h b/include/uapi/linux/ethtool.h
> index d1413538ef30..0495314ce20b 100644
> --- a/include/uapi/linux/ethtool.h
> +++ b/include/uapi/linux/ethtool.h
[...]
> @@ -556,6 +557,60 @@ enum {
> ETHTOOL_A_CABLE_TEST_TDR_NTF_MAX = __ETHTOOL_A_CABLE_TEST_TDR_NTF_CNT -
> 1
> };
>
> +/* TUNNEL INFO */
> +
> +enum {
> + ETHTOOL_A_TUNNEL_INFO_UNSPEC,
> + ETHTOOL_A_TUNNEL_INFO_HEADER, /* nest - _A_HEADER_* */
> +
> + ETHTOOL_A_TUNNEL_INFO_UDP_PORTS, /* nest - _UDP_TABLE */
> +
> + /* add new constants above here */
> + __ETHTOOL_A_TUNNEL_INFO_CNT,
> + ETHTOOL_A_TUNNEL_INFO_MAX = (__ETHTOOL_A_TUNNEL_INFO_CNT - 1)
> +};
nit: other requests with nested attributes have the enums ordered "from
inside out", i.e. nested attributes before the nest containing them.
> +
> +enum {
> + ETHTOOL_A_TUNNEL_UDP_UNSPEC,
> +
> + ETHTOOL_A_TUNNEL_UDP_TABLE, /* nest - _UDP_TABLE_*
> */
> +
> + /* add new constants above here */
> + __ETHTOOL_A_TUNNEL_UDP_CNT,
> + ETHTOOL_A_TUNNEL_UDP_MAX = (__ETHTOOL_A_TUNNEL_UDP_CNT - 1)
> +};
> +
> +enum {
> + ETHTOOL_A_TUNNEL_UDP_TABLE_UNSPEC,
> +
> + ETHTOOL_A_TUNNEL_UDP_TABLE_SIZE, /* u32 */
> + ETHTOOL_A_TUNNEL_UDP_TABLE_TYPES, /* u32 */
In the code below, this is a bitset, not u32.
> + ETHTOOL_A_TUNNEL_UDP_TABLE_ENTRY, /* nest - _UDP_ENTRY_*
> */
> +
> + /* add new constants above here */
> + __ETHTOOL_A_TUNNEL_UDP_TABLE_CNT,
> + ETHTOOL_A_TUNNEL_UDP_TABLE_MAX = (__ETHTOOL_A_TUNNEL_UDP_TABLE_CNT - 1)
> +};
> +
> +enum {
> + ETHTOOL_A_TUNNEL_UDP_ENTRY_UNSPEC,
> +
> + ETHTOOL_A_TUNNEL_UDP_ENTRY_PORT, /* be16 */
Do we get some benefit from passing the port in network byte order? It
would be helpful if we expected userspace to copy it e.g. into struct
sockaddr_in but that doesn't seem to be the case.
> + ETHTOOL_A_TUNNEL_UDP_ENTRY_TYPE, /* u32 */
> +
> + /* add new constants above here */
> + __ETHTOOL_A_TUNNEL_UDP_ENTRY_CNT,
> + ETHTOOL_A_TUNNEL_UDP_ENTRY_MAX = (__ETHTOOL_A_TUNNEL_UDP_ENTRY_CNT - 1)
> +};
> +
> +enum {
> + ETHTOOL_UDP_TUNNEL_TYPE_VXLAN,
> + ETHTOOL_UDP_TUNNEL_TYPE_GENEVE,
> + ETHTOOL_UDP_TUNNEL_TYPE_VXLAN_GPE,
> +
> + __ETHTOOL_UDP_TUNNEL_TYPE_BIT_CNT
nit: the "BIT" part looks inconsistent (like a leftover form an older
version where the constants were named differently).
> +};
> +
> /* generic netlink info */
> #define ETHTOOL_GENL_NAME "ethtool"
> #define ETHTOOL_GENL_VERSION 1
[...]
> diff --git a/net/ethtool/strset.c b/net/ethtool/strset.c
> index 0eed4e4909ab..5d3f315d4781 100644
> --- a/net/ethtool/strset.c
> +++ b/net/ethtool/strset.c
> @@ -75,6 +75,11 @@ static const struct strset_info info_template[] = {
> .count = __HWTSTAMP_FILTER_CNT,
> .strings = ts_rx_filter_names,
> },
> + [ETH_SS_UDP_TUNNEL_TYPES] = {
> + .per_dev = false,
> + .count = __ETHTOOL_A_TUNNEL_UDP_ENTRY_CNT,
This should be __ETHTOOL_UDP_TUNNEL_TYPE_BIT_CNT (number of strings in
the set, i.e. number of tunnel types).
> + .strings = udp_tunnel_type_names,
> + },
> };
>
> struct strset_req_info {
> diff --git a/net/ethtool/tunnels.c b/net/ethtool/tunnels.c
> new file mode 100644
> index 000000000000..e9e09ea08c6a
> --- /dev/null
> +++ b/net/ethtool/tunnels.c
> @@ -0,0 +1,261 @@
> +// SPDX-License-Identifier: GPL-2.0-only
> +
> +#include <linux/ethtool_netlink.h>
> +#include <net/udp_tunnel.h>
> +
> +#include "bitset.h"
> +#include "common.h"
> +#include "netlink.h"
> +
> +static const struct nla_policy
> +ethtool_tunnel_info_policy[ETHTOOL_A_TUNNEL_INFO_MAX + 1] = {
> + [ETHTOOL_A_TUNNEL_INFO_UNSPEC] = { .type = NLA_REJECT },
> + [ETHTOOL_A_TUNNEL_INFO_HEADER] = { .type = NLA_NESTED },
> +};
> +
> +static_assert(ETHTOOL_UDP_TUNNEL_TYPE_VXLAN == ilog2(UDP_TUNNEL_TYPE_VXLAN));
> +static_assert(ETHTOOL_UDP_TUNNEL_TYPE_GENEVE ==
> ilog2(UDP_TUNNEL_TYPE_GENEVE));
> +static_assert(ETHTOOL_UDP_TUNNEL_TYPE_VXLAN_GPE ==
> + ilog2(UDP_TUNNEL_TYPE_VXLAN_GPE));
> +
> +static ssize_t
> +ethnl_tunnel_info_reply_size(const struct ethnl_req_info *req_base,
> + struct netlink_ext_ack *extack)
> +{
> + bool compact = req_base->flags & ETHTOOL_FLAG_COMPACT_BITSETS;
> + const struct udp_tunnel_nic_info *info;
> + unsigned int i;
> + size_t size;
> + int ret;
> +
> + BUILD_BUG_ON(__ETHTOOL_UDP_TUNNEL_TYPE_BIT_CNT > 32);
> +
> + info = req_base->dev->udp_tunnel_nic_info;
> + if (!info) {
> + NL_SET_ERR_MSG(extack,
> + "device does not report tunnel offload info");
> + return -EOPNOTSUPP;
> + }
> +
> + size = nla_total_size(0); /* _INFO_UDP_PORTS */
> +
> + for (i = 0; i < UDP_TUNNEL_NIC_MAX_TABLES; i++) {
> + if (!info->tables[i].n_entries)
> + return size;
> +
> + size += nla_total_size(0); /* _UDP_TABLE */
> + size += nla_total_size(sizeof(u32)); /* _UDP_TABLE_SIZE */
> + ret = ethnl_bitset32_size(&info->tables[i].tunnel_types, NULL,
> + __ETHTOOL_UDP_TUNNEL_TYPE_BIT_CNT,
> + udp_tunnel_type_names, compact);
> + if (ret < 0)
> + return ret;
> + size += ret;
> +
> + size += udp_tunnel_nic_dump_size(req_base->dev, i);
> + }
> +
> + return size;
> +}
How big can the message get? Can we be sure the information for one
device will always fit into a reasonably sized message? Attribute
ETHTOOL_A_TUNNEL_INFO_UDP_PORTS is limited by 65535 bytes (attribute
size is u16), can we always fit into this size?
Michal
