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 for
bpf programs to see the Tx device.
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 <dsah...@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(+)
diff --git a/include/net/xdp.h b/include/net/xdp.h
index 90f11760bd12..d54022959491 100644
--- a/include/net/xdp.h
+++ b/include/net/xdp.h
@@ -61,12 +61,17 @@ 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;
void *data_meta;
void *data_hard_start;
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 02177049cf66..61ae81bf67de 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 */
};
/* DEVMAP values */
diff --git a/kernel/bpf/devmap.c b/kernel/bpf/devmap.c
index 3152151d3bb8..defdd22caa4b 100644
--- a/kernel/bpf/devmap.c
+++ b/kernel/bpf/devmap.c
@@ -467,8 +467,11 @@ 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_PASS:
diff --git a/net/core/filter.c b/net/core/filter.c
index a6fc23447f12..2e9dbfd8e60c 100644
--- a/net/core/filter.c
+++ b/net/core/filter.c
@@ -7014,6 +7014,13 @@ 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) {
@@ -7967,6 +7974,16 @@ 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 02177049cf66..61ae81bf67de 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 */
};
/* DEVMAP values */
--
2.21.1 (Apple Git-122.3)
