| Message ID | 20200522010526.14649-4-dsahern@kernel.org |
|---|---|
| State | RFC |
| Delegated to: | BPF Maintainers |
| Headers | show |
| Series | bpf: Add support for XDP programs in DEVMAPs | expand |
David Ahern <dsahern@kernel.org> writes: > Add xdp_txq_info as the Tx counterpart to xdp_rxq_info. At the > moment only the device is added. Other fields (queue_index) > can be added as use cases arise. > > From a UAPI perspective, add egress_ifindex to xdp context. > > Update the verifier to only allow accesses to egress_ifindex by > XDP programs with BPF_XDP_DEVMAP expected attach type. > > Signed-off-by: David Ahern <dsahern@kernel.org> Nit: seems a bit odd to order the patches like this, I'd have expected this patch to go before #2. -Toke
On 5/22/20 10:04 AM, Toke Høiland-Jørgensen wrote: > David Ahern <dsahern@kernel.org> writes: > >> Add xdp_txq_info as the Tx counterpart to xdp_rxq_info. At the >> moment only the device is added. Other fields (queue_index) >> can be added as use cases arise. >> >> From a UAPI perspective, add egress_ifindex to xdp context. >> >> Update the verifier to only allow accesses to egress_ifindex by >> XDP programs with BPF_XDP_DEVMAP expected attach type. >> >> Signed-off-by: David Ahern <dsahern@kernel.org> > > Nit: seems a bit odd to order the patches like this, I'd have expected > this patch to go before #2. > This patch depends on patch 2, so it needs to follow it.
diff --git a/include/net/xdp.h b/include/net/xdp.h index 3094fccf5a88..fd60ab3d401f 100644 --- a/include/net/xdp.h +++ b/include/net/xdp.h @@ -65,6 +65,10 @@ struct xdp_rxq_info { struct xdp_mem_info mem; } ____cacheline_aligned; /* perf critical, avoid false-sharing */ +struct xdp_txq_info { + struct net_device *dev; +}; + struct xdp_buff { void *data; void *data_end; @@ -72,6 +76,7 @@ struct xdp_buff { void *data_hard_start; unsigned long handle; struct xdp_rxq_info *rxq; + struct xdp_txq_info *txq; u32 frame_sz; /* frame size to deduce data_hard_end/reserved tailroom*/ }; diff --git a/include/uapi/linux/bpf.h b/include/uapi/linux/bpf.h index 8c2c0d0c9a0e..264de1484a66 100644 --- a/include/uapi/linux/bpf.h +++ b/include/uapi/linux/bpf.h @@ -3624,6 +3624,8 @@ struct xdp_md { /* Below access go through struct xdp_rxq_info */ __u32 ingress_ifindex; /* rxq->dev->ifindex */ __u32 rx_queue_index; /* rxq->queue_index */ + + __u32 egress_ifindex; /* txq->dev->ifindex */ }; enum sk_action { diff --git a/kernel/bpf/devmap.c b/kernel/bpf/devmap.c index 06f4c746fa7c..240c1aeca7ef 100644 --- a/kernel/bpf/devmap.c +++ b/kernel/bpf/devmap.c @@ -471,8 +471,11 @@ static struct xdp_buff *dev_map_run_prog(struct net_device *dev, struct xdp_buff *xdp, struct bpf_prog *xdp_prog) { + struct xdp_txq_info txq = { .dev = dev }; u32 act; + xdp->txq = &txq; + act = bpf_prog_run_xdp(xdp_prog, xdp); switch (act) { case XDP_DROP: diff --git a/net/core/filter.c b/net/core/filter.c index bd2853d23b50..199e02a30381 100644 --- a/net/core/filter.c +++ b/net/core/filter.c @@ -6994,6 +6994,13 @@ static bool xdp_is_valid_access(int off, int size, const struct bpf_prog *prog, struct bpf_insn_access_aux *info) { + if (prog->expected_attach_type != BPF_XDP_DEVMAP) { + switch (off) { + case offsetof(struct xdp_md, egress_ifindex): + return false; + } + } + if (type == BPF_WRITE) { if (bpf_prog_is_dev_bound(prog->aux)) { switch (off) { @@ -7942,6 +7949,16 @@ static u32 xdp_convert_ctx_access(enum bpf_access_type type, offsetof(struct xdp_rxq_info, queue_index)); break; + case offsetof(struct xdp_md, egress_ifindex): + *insn++ = BPF_LDX_MEM(BPF_FIELD_SIZEOF(struct xdp_buff, txq), + si->dst_reg, si->src_reg, + offsetof(struct xdp_buff, txq)); + *insn++ = BPF_LDX_MEM(BPF_FIELD_SIZEOF(struct xdp_txq_info, dev), + si->dst_reg, si->dst_reg, + offsetof(struct xdp_txq_info, dev)); + *insn++ = BPF_LDX_MEM(BPF_W, si->dst_reg, si->dst_reg, + offsetof(struct net_device, ifindex)); + break; } return insn - insn_buf; diff --git a/tools/include/uapi/linux/bpf.h b/tools/include/uapi/linux/bpf.h index 8c2c0d0c9a0e..264de1484a66 100644 --- a/tools/include/uapi/linux/bpf.h +++ b/tools/include/uapi/linux/bpf.h @@ -3624,6 +3624,8 @@ struct xdp_md { /* Below access go through struct xdp_rxq_info */ __u32 ingress_ifindex; /* rxq->dev->ifindex */ __u32 rx_queue_index; /* rxq->queue_index */ + + __u32 egress_ifindex; /* txq->dev->ifindex */ }; enum sk_action {
Add xdp_txq_info as the Tx counterpart to xdp_rxq_info. At the moment only the device is added. Other fields (queue_index) can be added as use cases arise. From a UAPI perspective, add egress_ifindex to xdp context. Update the verifier to only allow accesses to egress_ifindex by XDP programs with BPF_XDP_DEVMAP expected attach type. Signed-off-by: David Ahern <dsahern@kernel.org> --- include/net/xdp.h | 5 +++++ include/uapi/linux/bpf.h | 2 ++ kernel/bpf/devmap.c | 3 +++ net/core/filter.c | 17 +++++++++++++++++ tools/include/uapi/linux/bpf.h | 2 ++ 5 files changed, 29 insertions(+)