From e6795330f88b4f643c649a02662d47b779340535 Mon Sep 17 00:00:00 2001 From: Larysa Zaremba Date: Tue, 5 Dec 2023 22:08:38 +0100 Subject: [PATCH] xdp: Add VLAN tag hint Implement functionality that enables drivers to expose VLAN tag to XDP code. VLAN tag is represented by 2 variables: - protocol ID, which is passed to bpf code in BE - VLAN TCI, in host byte order Acked-by: Stanislav Fomichev Signed-off-by: Larysa Zaremba Acked-by: Jesper Dangaard Brouer Link: https://lore.kernel.org/r/20231205210847.28460-10-larysa.zaremba@intel.com Signed-off-by: Alexei Starovoitov --- Documentation/netlink/specs/netdev.yaml | 4 +++ Documentation/networking/xdp-rx-metadata.rst | 8 ++++- include/net/xdp.h | 6 ++++ include/uapi/linux/netdev.h | 3 ++ net/core/xdp.c | 33 ++++++++++++++++++++ tools/include/uapi/linux/netdev.h | 3 ++ tools/net/ynl/generated/netdev-user.c | 1 + 7 files changed, 57 insertions(+), 1 deletion(-) diff --git a/Documentation/netlink/specs/netdev.yaml b/Documentation/netlink/specs/netdev.yaml index eef6358ec587..aeec090e1387 100644 --- a/Documentation/netlink/specs/netdev.yaml +++ b/Documentation/netlink/specs/netdev.yaml @@ -54,6 +54,10 @@ definitions: name: hash doc: Device is capable of exposing receive packet hash via bpf_xdp_metadata_rx_hash(). + - + name: vlan-tag + doc: + Device is capable of exposing receive packet VLAN tag via bpf_xdp_metadata_rx_vlan_tag(). - type: flags name: xsk-flags diff --git a/Documentation/networking/xdp-rx-metadata.rst b/Documentation/networking/xdp-rx-metadata.rst index e3e9420fd817..a6e0ece18be5 100644 --- a/Documentation/networking/xdp-rx-metadata.rst +++ b/Documentation/networking/xdp-rx-metadata.rst @@ -20,7 +20,13 @@ Currently, the following kfuncs are supported. In the future, as more metadata is supported, this set will grow: .. kernel-doc:: net/core/xdp.c - :identifiers: bpf_xdp_metadata_rx_timestamp bpf_xdp_metadata_rx_hash + :identifiers: bpf_xdp_metadata_rx_timestamp + +.. kernel-doc:: net/core/xdp.c + :identifiers: bpf_xdp_metadata_rx_hash + +.. kernel-doc:: net/core/xdp.c + :identifiers: bpf_xdp_metadata_rx_vlan_tag An XDP program can use these kfuncs to read the metadata into stack variables for its own consumption. Or, to pass the metadata on to other diff --git a/include/net/xdp.h b/include/net/xdp.h index b7d6fe61381f..8cd04a74dba5 100644 --- a/include/net/xdp.h +++ b/include/net/xdp.h @@ -404,6 +404,10 @@ void xdp_attachment_setup(struct xdp_attachment_info *info, NETDEV_XDP_RX_METADATA_HASH, \ bpf_xdp_metadata_rx_hash, \ xmo_rx_hash) \ + XDP_METADATA_KFUNC(XDP_METADATA_KFUNC_RX_VLAN_TAG, \ + NETDEV_XDP_RX_METADATA_VLAN_TAG, \ + bpf_xdp_metadata_rx_vlan_tag, \ + xmo_rx_vlan_tag) \ enum xdp_rx_metadata { #define XDP_METADATA_KFUNC(name, _, __, ___) name, @@ -465,6 +469,8 @@ struct xdp_metadata_ops { int (*xmo_rx_timestamp)(const struct xdp_md *ctx, u64 *timestamp); int (*xmo_rx_hash)(const struct xdp_md *ctx, u32 *hash, enum xdp_rss_hash_type *rss_type); + int (*xmo_rx_vlan_tag)(const struct xdp_md *ctx, __be16 *vlan_proto, + u16 *vlan_tci); }; #ifdef CONFIG_NET diff --git a/include/uapi/linux/netdev.h b/include/uapi/linux/netdev.h index 6244c0164976..966638b08ccf 100644 --- a/include/uapi/linux/netdev.h +++ b/include/uapi/linux/netdev.h @@ -44,10 +44,13 @@ enum netdev_xdp_act { * timestamp via bpf_xdp_metadata_rx_timestamp(). * @NETDEV_XDP_RX_METADATA_HASH: Device is capable of exposing receive packet * hash via bpf_xdp_metadata_rx_hash(). + * @NETDEV_XDP_RX_METADATA_VLAN_TAG: Device is capable of exposing receive + * packet VLAN tag via bpf_xdp_metadata_rx_vlan_tag(). */ enum netdev_xdp_rx_metadata { NETDEV_XDP_RX_METADATA_TIMESTAMP = 1, NETDEV_XDP_RX_METADATA_HASH = 2, + NETDEV_XDP_RX_METADATA_VLAN_TAG = 4, }; /** diff --git a/net/core/xdp.c b/net/core/xdp.c index b6f1d6dab3f2..4869c1c2d8f3 100644 --- a/net/core/xdp.c +++ b/net/core/xdp.c @@ -736,6 +736,39 @@ __bpf_kfunc int bpf_xdp_metadata_rx_hash(const struct xdp_md *ctx, u32 *hash, return -EOPNOTSUPP; } +/** + * bpf_xdp_metadata_rx_vlan_tag - Get XDP packet outermost VLAN tag + * @ctx: XDP context pointer. + * @vlan_proto: Destination pointer for VLAN Tag protocol identifier (TPID). + * @vlan_tci: Destination pointer for VLAN TCI (VID + DEI + PCP) + * + * In case of success, ``vlan_proto`` contains *Tag protocol identifier (TPID)*, + * usually ``ETH_P_8021Q`` or ``ETH_P_8021AD``, but some networks can use + * custom TPIDs. ``vlan_proto`` is stored in **network byte order (BE)** + * and should be used as follows: + * ``if (vlan_proto == bpf_htons(ETH_P_8021Q)) do_something();`` + * + * ``vlan_tci`` contains the remaining 16 bits of a VLAN tag. + * Driver is expected to provide those in **host byte order (usually LE)**, + * so the bpf program should not perform byte conversion. + * According to 802.1Q standard, *VLAN TCI (Tag control information)* + * is a bit field that contains: + * *VLAN identifier (VID)* that can be read with ``vlan_tci & 0xfff``, + * *Drop eligible indicator (DEI)* - 1 bit, + * *Priority code point (PCP)* - 3 bits. + * For detailed meaning of DEI and PCP, please refer to other sources. + * + * Return: + * * Returns 0 on success or ``-errno`` on error. + * * ``-EOPNOTSUPP`` : device driver doesn't implement kfunc + * * ``-ENODATA`` : VLAN tag was not stripped or is not available + */ +__bpf_kfunc int bpf_xdp_metadata_rx_vlan_tag(const struct xdp_md *ctx, + __be16 *vlan_proto, u16 *vlan_tci) +{ + return -EOPNOTSUPP; +} + __bpf_kfunc_end_defs(); BTF_SET8_START(xdp_metadata_kfunc_ids) diff --git a/tools/include/uapi/linux/netdev.h b/tools/include/uapi/linux/netdev.h index 6244c0164976..966638b08ccf 100644 --- a/tools/include/uapi/linux/netdev.h +++ b/tools/include/uapi/linux/netdev.h @@ -44,10 +44,13 @@ enum netdev_xdp_act { * timestamp via bpf_xdp_metadata_rx_timestamp(). * @NETDEV_XDP_RX_METADATA_HASH: Device is capable of exposing receive packet * hash via bpf_xdp_metadata_rx_hash(). + * @NETDEV_XDP_RX_METADATA_VLAN_TAG: Device is capable of exposing receive + * packet VLAN tag via bpf_xdp_metadata_rx_vlan_tag(). */ enum netdev_xdp_rx_metadata { NETDEV_XDP_RX_METADATA_TIMESTAMP = 1, NETDEV_XDP_RX_METADATA_HASH = 2, + NETDEV_XDP_RX_METADATA_VLAN_TAG = 4, }; /** diff --git a/tools/net/ynl/generated/netdev-user.c b/tools/net/ynl/generated/netdev-user.c index 3b9dee94d4ce..e3fe748086bd 100644 --- a/tools/net/ynl/generated/netdev-user.c +++ b/tools/net/ynl/generated/netdev-user.c @@ -53,6 +53,7 @@ const char *netdev_xdp_act_str(enum netdev_xdp_act value) static const char * const netdev_xdp_rx_metadata_strmap[] = { [0] = "timestamp", [1] = "hash", + [2] = "vlan-tag", }; const char *netdev_xdp_rx_metadata_str(enum netdev_xdp_rx_metadata value)