From 0d8300325660f81787892a1c58dc1f9428a67143 Mon Sep 17 00:00:00 2001 From: Jakub Kicinski Date: Tue, 8 May 2018 19:37:06 -0700 Subject: [PATCH] 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 Reviewed-by: Quentin Monnet Signed-off-by: Daniel Borkmann --- include/linux/bpf.h | 2 +- kernel/bpf/verifier.c | 2 +- net/core/filter.c | 9 ++++++++- 3 files changed, 10 insertions(+), 3 deletions(-) diff --git a/include/linux/bpf.h b/include/linux/bpf.h index 321969da67b7..a38e474bf7ee 100644 --- a/include/linux/bpf.h +++ b/include/linux/bpf.h @@ -627,7 +627,7 @@ bool bpf_offload_dev_match(struct bpf_prog *prog, struct bpf_map *map); #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 d5e1a6c4165d..d92d9c37affd 100644 --- a/kernel/bpf/verifier.c +++ b/kernel/bpf/verifier.c @@ -5215,7 +5215,7 @@ static int convert_ctx_accesses(struct bpf_verifier_env *env) } } - 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 6877426c23a6..0baa715e4699 100644 --- a/net/core/filter.c +++ b/net/core/filter.c @@ -4645,8 +4645,15 @@ static bool xdp_is_valid_access(int off, int size, 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): -- 2.45.2