bpf: xdp: allow offloads to store into rx_queue_index
It's fairly easy for offloaded XDP programs to select the RX queue
packets go to. We need a way of expressing this in the software.
Allow write to the rx_queue_index field of struct xdp_md for
device-bound programs.
Skip convert_ctx_access callback entirely for offloads.
Signed-off-by: Jakub Kicinski <jakub.kicinski@netronome.com>
Reviewed-by: Quentin Monnet <quentin.monnet@netronome.com>
Signed-off-by: Daniel Borkmann <daniel@iogearbox.net>
diff --git a/include/linux/bpf.h b/include/linux/bpf.h
index 321969d..a38e474 100644
--- a/include/linux/bpf.h
+++ b/include/linux/bpf.h
@@ -627,7 +627,7 @@
#if defined(CONFIG_NET) && defined(CONFIG_BPF_SYSCALL)
int bpf_prog_offload_init(struct bpf_prog *prog, union bpf_attr *attr);
-static inline bool bpf_prog_is_dev_bound(struct bpf_prog_aux *aux)
+static inline bool bpf_prog_is_dev_bound(const struct bpf_prog_aux *aux)
{
return aux->offload_requested;
}
diff --git a/kernel/bpf/verifier.c b/kernel/bpf/verifier.c
index d5e1a6c..d92d9c37 100644
--- a/kernel/bpf/verifier.c
+++ b/kernel/bpf/verifier.c
@@ -5215,7 +5215,7 @@
}
}
- if (!ops->convert_ctx_access)
+ if (!ops->convert_ctx_access || bpf_prog_is_dev_bound(env->prog->aux))
return 0;
insn = env->prog->insnsi + delta;
diff --git a/net/core/filter.c b/net/core/filter.c
index 6877426..0baa715 100644
--- a/net/core/filter.c
+++ b/net/core/filter.c
@@ -4645,8 +4645,15 @@
const struct bpf_prog *prog,
struct bpf_insn_access_aux *info)
{
- if (type == BPF_WRITE)
+ if (type == BPF_WRITE) {
+ if (bpf_prog_is_dev_bound(prog->aux)) {
+ switch (off) {
+ case offsetof(struct xdp_md, rx_queue_index):
+ return __is_valid_xdp_access(off, size);
+ }
+ }
return false;
+ }
switch (off) {
case offsetof(struct xdp_md, data):