lists.openwall.net   lists  /  announce  owl-users  owl-dev  john-users  john-dev  passwdqc-users  yescrypt  popa3d-users  /  oss-security  kernel-hardening  musl  sabotage  tlsify  passwords  /  crypt-dev  xvendor  /  Bugtraq  Full-Disclosure  linux-kernel  linux-netdev  linux-ext4  linux-hardening  linux-cve-announce  PHC 
Open Source and information security mailing list archives
 
Hash Suite: Windows password security audit tool. GUI, reports in PDF.
[<prev] [next>] [thread-next>] [day] [month] [year] [list]
Date:   Tue, 21 Mar 2023 14:52:31 +0100
From:   Jesper Dangaard Brouer <brouer@...hat.com>
To:     bpf@...r.kernel.org
Cc:     Jesper Dangaard Brouer <brouer@...hat.com>, netdev@...r.kernel.org,
        Stanislav Fomichev <sdf@...gle.com>, martin.lau@...nel.org,
        ast@...nel.org, daniel@...earbox.net, alexandr.lobakin@...el.com,
        larysa.zaremba@...el.com, xdp-hints@...-project.net,
        anthony.l.nguyen@...el.com, yoong.siang.song@...el.com,
        boon.leong.ong@...el.com, intel-wired-lan@...ts.osuosl.org,
        pabeni@...hat.com, jesse.brandeburg@...el.com, kuba@...nel.org,
        edumazet@...gle.com, john.fastabend@...il.com, hawk@...nel.org,
        davem@...emloft.net
Subject: [PATCH bpf V2] xdp: bpf_xdp_metadata use EOPNOTSUPP for no driver
 support

When driver doesn't implement a bpf_xdp_metadata kfunc the fallback
implementation returns EOPNOTSUPP, which indicate device driver doesn't
implement this kfunc.

Currently many drivers also return EOPNOTSUPP when the hint isn't
available, which is ambiguous from an API point of view. Instead
change drivers to return ENODATA in these cases.

There can be natural cases why a driver doesn't provide any hardware
info for a specific hint, even on a frame to frame basis (e.g. PTP).
Lets keep these cases as separate return codes.

When describing the return values, adjust the function kernel-doc layout
to get proper rendering for the return values.

Fixes: ab46182d0dcb ("net/mlx4_en: Support RX XDP metadata")
Fixes: bc8d405b1ba9 ("net/mlx5e: Support RX XDP metadata")
Fixes: 306531f0249f ("veth: Support RX XDP metadata")
Fixes: 3d76a4d3d4e5 ("bpf: XDP metadata RX kfuncs")
Signed-off-by: Jesper Dangaard Brouer <brouer@...hat.com>
---
 Documentation/networking/xdp-rx-metadata.rst     |    7 +++++--
 drivers/net/ethernet/mellanox/mlx4/en_rx.c       |    4 ++--
 drivers/net/ethernet/mellanox/mlx5/core/en/xdp.c |    4 ++--
 drivers/net/veth.c                               |    4 ++--
 net/core/xdp.c                                   |   10 ++++++++--
 5 files changed, 19 insertions(+), 10 deletions(-)

diff --git a/Documentation/networking/xdp-rx-metadata.rst b/Documentation/networking/xdp-rx-metadata.rst
index aac63fc2d08b..25ce72af81c2 100644
--- a/Documentation/networking/xdp-rx-metadata.rst
+++ b/Documentation/networking/xdp-rx-metadata.rst
@@ -23,10 +23,13 @@ metadata is supported, this set will grow:
 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
 consumers, an XDP program can store it into the metadata area carried
-ahead of the packet.
+ahead of the packet. Not all packets will necessary have the requested
+metadata available in which case the driver returns ``-ENODATA``.
 
 Not all kfuncs have to be implemented by the device driver; when not
-implemented, the default ones that return ``-EOPNOTSUPP`` will be used.
+implemented, the default ones that return ``-EOPNOTSUPP`` will be used
+to indicate the device driver have not implemented this kfunc.
+
 
 Within an XDP frame, the metadata layout (accessed via ``xdp_buff``) is
 as follows::
diff --git a/drivers/net/ethernet/mellanox/mlx4/en_rx.c b/drivers/net/ethernet/mellanox/mlx4/en_rx.c
index 0869d4fff17b..4b5e459b6d49 100644
--- a/drivers/net/ethernet/mellanox/mlx4/en_rx.c
+++ b/drivers/net/ethernet/mellanox/mlx4/en_rx.c
@@ -674,7 +674,7 @@ int mlx4_en_xdp_rx_timestamp(const struct xdp_md *ctx, u64 *timestamp)
 	struct mlx4_en_xdp_buff *_ctx = (void *)ctx;
 
 	if (unlikely(_ctx->ring->hwtstamp_rx_filter != HWTSTAMP_FILTER_ALL))
-		return -EOPNOTSUPP;
+		return -ENODATA;
 
 	*timestamp = mlx4_en_get_hwtstamp(_ctx->mdev,
 					  mlx4_en_get_cqe_ts(_ctx->cqe));
@@ -686,7 +686,7 @@ int mlx4_en_xdp_rx_hash(const struct xdp_md *ctx, u32 *hash)
 	struct mlx4_en_xdp_buff *_ctx = (void *)ctx;
 
 	if (unlikely(!(_ctx->dev->features & NETIF_F_RXHASH)))
-		return -EOPNOTSUPP;
+		return -ENODATA;
 
 	*hash = be32_to_cpu(_ctx->cqe->immed_rss_invalid);
 	return 0;
diff --git a/drivers/net/ethernet/mellanox/mlx5/core/en/xdp.c b/drivers/net/ethernet/mellanox/mlx5/core/en/xdp.c
index bcd6370de440..c5dae48b7932 100644
--- a/drivers/net/ethernet/mellanox/mlx5/core/en/xdp.c
+++ b/drivers/net/ethernet/mellanox/mlx5/core/en/xdp.c
@@ -162,7 +162,7 @@ static int mlx5e_xdp_rx_timestamp(const struct xdp_md *ctx, u64 *timestamp)
 	const struct mlx5e_xdp_buff *_ctx = (void *)ctx;
 
 	if (unlikely(!mlx5e_rx_hw_stamp(_ctx->rq->tstamp)))
-		return -EOPNOTSUPP;
+		return -ENODATA;
 
 	*timestamp =  mlx5e_cqe_ts_to_ns(_ctx->rq->ptp_cyc2time,
 					 _ctx->rq->clock, get_cqe_ts(_ctx->cqe));
@@ -174,7 +174,7 @@ static int mlx5e_xdp_rx_hash(const struct xdp_md *ctx, u32 *hash)
 	const struct mlx5e_xdp_buff *_ctx = (void *)ctx;
 
 	if (unlikely(!(_ctx->xdp.rxq->dev->features & NETIF_F_RXHASH)))
-		return -EOPNOTSUPP;
+		return -ENODATA;
 
 	*hash = be32_to_cpu(_ctx->cqe->rss_hash_result);
 	return 0;
diff --git a/drivers/net/veth.c b/drivers/net/veth.c
index 1bb54de7124d..046461ee42ea 100644
--- a/drivers/net/veth.c
+++ b/drivers/net/veth.c
@@ -1610,7 +1610,7 @@ static int veth_xdp_rx_timestamp(const struct xdp_md *ctx, u64 *timestamp)
 	struct veth_xdp_buff *_ctx = (void *)ctx;
 
 	if (!_ctx->skb)
-		return -EOPNOTSUPP;
+		return -ENODATA;
 
 	*timestamp = skb_hwtstamps(_ctx->skb)->hwtstamp;
 	return 0;
@@ -1621,7 +1621,7 @@ static int veth_xdp_rx_hash(const struct xdp_md *ctx, u32 *hash)
 	struct veth_xdp_buff *_ctx = (void *)ctx;
 
 	if (!_ctx->skb)
-		return -EOPNOTSUPP;
+		return -ENODATA;
 
 	*hash = skb_get_hash(_ctx->skb);
 	return 0;
diff --git a/net/core/xdp.c b/net/core/xdp.c
index 8d3ad315f18d..7133017bcd74 100644
--- a/net/core/xdp.c
+++ b/net/core/xdp.c
@@ -705,7 +705,10 @@ __diag_ignore_all("-Wmissing-prototypes",
  * @ctx: XDP context pointer.
  * @timestamp: Return value pointer.
  *
- * Returns 0 on success or ``-errno`` on error.
+ * Return:
+ * * Returns 0 on success or ``-errno`` on error.
+ * * ``-EOPNOTSUPP`` : means device driver does not implement kfunc
+ * * ``-ENODATA``    : means no RX-timestamp available for this frame
  */
 __bpf_kfunc int bpf_xdp_metadata_rx_timestamp(const struct xdp_md *ctx, u64 *timestamp)
 {
@@ -717,7 +720,10 @@ __bpf_kfunc int bpf_xdp_metadata_rx_timestamp(const struct xdp_md *ctx, u64 *tim
  * @ctx: XDP context pointer.
  * @hash: Return value pointer.
  *
- * Returns 0 on success or ``-errno`` on error.
+ * Return:
+ * * Returns 0 on success or ``-errno`` on error.
+ * * ``-EOPNOTSUPP`` : means device driver doesn't implement kfunc
+ * * ``-ENODATA``    : means no RX-hash available for this frame
  */
 __bpf_kfunc int bpf_xdp_metadata_rx_hash(const struct xdp_md *ctx, u32 *hash)
 {


Powered by blists - more mailing lists

Powered by Openwall GNU/*/Linux Powered by OpenVZ