| Message ID | 20230824192703.712881-10-larysa.zaremba@intel.com (mailing list archive) |
|---|---|
| State | RFC |
| Delegated to: | BPF |
| Headers | show |
| Series | XDP metadata via kfuncs for ice + mlx5 | expand |
From: Larysa Zaremba <larysa.zaremba@intel.com> Date: Thu, 24 Aug 2023 21:26:48 +0200 > Implement functionality that enables drivers to expose VLAN tag > to XDP code. I'd leave a couple more words here. Mention that it exports both tag and protocol, for example. That TCI is host-Endian and proto is BE (just like how skb stores them and it's fine). > > Signed-off-by: Larysa Zaremba <larysa.zaremba@intel.com> > --- > Documentation/networking/xdp-rx-metadata.rst | 8 ++++- > include/net/xdp.h | 4 +++ > kernel/bpf/offload.c | 2 ++ > net/core/xdp.c | 34 ++++++++++++++++++++ > 4 files changed, 47 insertions(+), 1 deletion(-) > > diff --git a/Documentation/networking/xdp-rx-metadata.rst b/Documentation/networking/xdp-rx-metadata.rst > index 25ce72af81c2..ea6dd79a21d3 100644 > --- a/Documentation/networking/xdp-rx-metadata.rst > +++ b/Documentation/networking/xdp-rx-metadata.rst > @@ -18,7 +18,13 @@ 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 1e9870d5f025..8bb64fc76498 100644 > --- a/include/net/xdp.h > +++ b/include/net/xdp.h > @@ -388,6 +388,8 @@ void xdp_attachment_setup(struct xdp_attachment_info *info, > bpf_xdp_metadata_rx_timestamp) \ > XDP_METADATA_KFUNC(XDP_METADATA_KFUNC_RX_HASH, \ > bpf_xdp_metadata_rx_hash) \ > + XDP_METADATA_KFUNC(XDP_METADATA_KFUNC_RX_VLAN_TAG, \ > + bpf_xdp_metadata_rx_vlan_tag) \ > > enum { > #define XDP_METADATA_KFUNC(name, _) name, > @@ -449,6 +451,8 @@ 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, u16 *vlan_tci, > + __be16 *vlan_proto); Was "TCI first, proto second" aligned with something or I can ask "why not proto first, TCI second"? > }; > > #ifdef CONFIG_NET [...] Thanks, Olek
On Thu, Sep 14, 2023 at 06:18:40PM +0200, Alexander Lobakin wrote: > From: Larysa Zaremba <larysa.zaremba@intel.com> > Date: Thu, 24 Aug 2023 21:26:48 +0200 > > > Implement functionality that enables drivers to expose VLAN tag > > to XDP code. > > I'd leave a couple more words here. Mention that it exports both tag and > protocol, for example. That TCI is host-Endian and proto is BE (just > like how skb stores them and it's fine). > OK > > > > Signed-off-by: Larysa Zaremba <larysa.zaremba@intel.com> > > --- > > Documentation/networking/xdp-rx-metadata.rst | 8 ++++- > > include/net/xdp.h | 4 +++ > > kernel/bpf/offload.c | 2 ++ > > net/core/xdp.c | 34 ++++++++++++++++++++ > > 4 files changed, 47 insertions(+), 1 deletion(-) > > > > diff --git a/Documentation/networking/xdp-rx-metadata.rst b/Documentation/networking/xdp-rx-metadata.rst > > index 25ce72af81c2..ea6dd79a21d3 100644 > > --- a/Documentation/networking/xdp-rx-metadata.rst > > +++ b/Documentation/networking/xdp-rx-metadata.rst > > @@ -18,7 +18,13 @@ 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 1e9870d5f025..8bb64fc76498 100644 > > --- a/include/net/xdp.h > > +++ b/include/net/xdp.h > > @@ -388,6 +388,8 @@ void xdp_attachment_setup(struct xdp_attachment_info *info, > > bpf_xdp_metadata_rx_timestamp) \ > > XDP_METADATA_KFUNC(XDP_METADATA_KFUNC_RX_HASH, \ > > bpf_xdp_metadata_rx_hash) \ > > + XDP_METADATA_KFUNC(XDP_METADATA_KFUNC_RX_VLAN_TAG, \ > > + bpf_xdp_metadata_rx_vlan_tag) \ > > > > enum { > > #define XDP_METADATA_KFUNC(name, _) name, > > @@ -449,6 +451,8 @@ 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, u16 *vlan_tci, > > + __be16 *vlan_proto); > > Was "TCI first, proto second" aligned with something or I can ask "why > not proto first, TCI second"? No particular reason. Now I have looked it up and this is the other way in all places >_<. I do probably need to switch this. Time to put my regular expressions skills to the test. > > > }; > > > > #ifdef CONFIG_NET > > [...] > > Thanks, > Olek
diff --git a/Documentation/networking/xdp-rx-metadata.rst b/Documentation/networking/xdp-rx-metadata.rst index 25ce72af81c2..ea6dd79a21d3 100644 --- a/Documentation/networking/xdp-rx-metadata.rst +++ b/Documentation/networking/xdp-rx-metadata.rst @@ -18,7 +18,13 @@ 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 1e9870d5f025..8bb64fc76498 100644 --- a/include/net/xdp.h +++ b/include/net/xdp.h @@ -388,6 +388,8 @@ void xdp_attachment_setup(struct xdp_attachment_info *info, bpf_xdp_metadata_rx_timestamp) \ XDP_METADATA_KFUNC(XDP_METADATA_KFUNC_RX_HASH, \ bpf_xdp_metadata_rx_hash) \ + XDP_METADATA_KFUNC(XDP_METADATA_KFUNC_RX_VLAN_TAG, \ + bpf_xdp_metadata_rx_vlan_tag) \ enum { #define XDP_METADATA_KFUNC(name, _) name, @@ -449,6 +451,8 @@ 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, u16 *vlan_tci, + __be16 *vlan_proto); }; #ifdef CONFIG_NET diff --git a/kernel/bpf/offload.c b/kernel/bpf/offload.c index 3e4f2ec1af06..8be340cf06f9 100644 --- a/kernel/bpf/offload.c +++ b/kernel/bpf/offload.c @@ -849,6 +849,8 @@ void *bpf_dev_bound_resolve_kfunc(struct bpf_prog *prog, u32 func_id) p = ops->xmo_rx_timestamp; else if (func_id == bpf_xdp_metadata_kfunc_id(XDP_METADATA_KFUNC_RX_HASH)) p = ops->xmo_rx_hash; + else if (func_id == bpf_xdp_metadata_kfunc_id(XDP_METADATA_KFUNC_RX_VLAN_TAG)) + p = ops->xmo_rx_vlan_tag; out: up_read(&bpf_devs_lock); diff --git a/net/core/xdp.c b/net/core/xdp.c index a70670fe9a2d..856e02bb4ce6 100644 --- a/net/core/xdp.c +++ b/net/core/xdp.c @@ -738,6 +738,40 @@ __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_tci: Destination pointer for VLAN TCI (VID + DEI + PCP) + * @vlan_proto: Destination pointer for VLAN Tag protocol identifier (TPID). + * + * 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, + u16 *vlan_tci, + __be16 *vlan_proto) +{ + return -EOPNOTSUPP; +} + __diag_pop(); BTF_SET8_START(xdp_metadata_kfunc_ids)
Implement functionality that enables drivers to expose VLAN tag to XDP code. Signed-off-by: Larysa Zaremba <larysa.zaremba@intel.com> --- Documentation/networking/xdp-rx-metadata.rst | 8 ++++- include/net/xdp.h | 4 +++ kernel/bpf/offload.c | 2 ++ net/core/xdp.c | 34 ++++++++++++++++++++ 4 files changed, 47 insertions(+), 1 deletion(-)