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authorDavid Ahern <dsahern@kernel.org>2020-05-29 16:07:14 -0600
committerAlexei Starovoitov <ast@kernel.org>2020-06-01 14:48:32 -0700
commit64b59025c15b244c0954cf52b24fbabfcf5ed8f6 (patch)
tree6d47a7f0f047306a1aede92a803a50e629b6c50a
parentfbee97feed9b3e4acdf9590e1f6b4a2eefecfffe (diff)
downloadlinux-64b59025c15b244c0954cf52b24fbabfcf5ed8f6.tar.bz2
xdp: Add xdp_txq_info to xdp_buff
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 <dsahern@kernel.org> Signed-off-by: Alexei Starovoitov <ast@kernel.org> Acked-by: Toke Høiland-Jørgensen <toke@redhat.com> Link: https://lore.kernel.org/bpf/20200529220716.75383-4-dsahern@kernel.org Signed-off-by: Alexei Starovoitov <ast@kernel.org>
-rw-r--r--include/net/xdp.h5
-rw-r--r--include/uapi/linux/bpf.h2
-rw-r--r--kernel/bpf/devmap.c3
-rw-r--r--net/core/filter.c17
-rw-r--r--tools/include/uapi/linux/bpf.h2
5 files changed, 29 insertions, 0 deletions
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 f1e364d69007..f862a58fb567 100644
--- a/include/uapi/linux/bpf.h
+++ b/include/uapi/linux/bpf.h
@@ -3707,6 +3707,8 @@ 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 0089d56617ec..c04fb1c72f5e 100644
--- a/kernel/bpf/devmap.c
+++ b/kernel/bpf/devmap.c
@@ -476,8 +476,11 @@ 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 0008b029d644..85ff827aab73 100644
--- a/net/core/filter.c
+++ b/net/core/filter.c
@@ -7015,6 +7015,13 @@ 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) {
@@ -7985,6 +7992,16 @@ 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 65d7717bce2f..f74bc4a2385e 100644
--- a/tools/include/uapi/linux/bpf.h
+++ b/tools/include/uapi/linux/bpf.h
@@ -3706,6 +3706,8 @@ 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 {