[PATCH v4 bpf-next 10/13] bpf: test_run: add skb_shared_info pointer in bpf_test_finish signature
From: Lorenzo Bianconi <lorenzo@kernel.org>
Date: 2020-10-02 14:43:10
Also in:
bpf
Subsystem:
bpf [general] (safe dynamic programs and tools), networking [general], the rest · Maintainers:
Alexei Starovoitov, Daniel Borkmann, Andrii Nakryiko, Eduard Zingerman, Kumar Kartikeya Dwivedi, "David S. Miller", Eric Dumazet, Jakub Kicinski, Paolo Abeni, Linus Torvalds
introduce skb_shared_info pointer in bpf_test_finish signature in order to copy back paged data from a xdp multi-buff frame to userspace buffer Tested-by: Eelco Chaudron <echaudro@redhat.com> Signed-off-by: Lorenzo Bianconi <lorenzo@kernel.org> --- net/bpf/test_run.c | 58 ++++++++++++++++++++++++++++++++++++++++------ 1 file changed, 51 insertions(+), 7 deletions(-)
diff --git a/net/bpf/test_run.c b/net/bpf/test_run.c
index ec7286cd051b..7e33181f88ee 100644
--- a/net/bpf/test_run.c
+++ b/net/bpf/test_run.c@@ -79,9 +79,23 @@ static int bpf_test_run(struct bpf_prog *prog, void *ctx, u32 repeat, return ret; } +static int bpf_test_get_buff_data_len(struct skb_shared_info *sinfo) +{ + int i, size = 0; + + if (likely(!sinfo)) + return 0; + + for (i = 0; i < sinfo->nr_frags; i++) + size += skb_frag_size(&sinfo->frags[i]); + + return size; +} + static int bpf_test_finish(const union bpf_attr *kattr, union bpf_attr __user *uattr, const void *data, - u32 size, u32 retval, u32 duration) + struct skb_shared_info *sinfo, u32 size, + u32 retval, u32 duration) { void __user *data_out = u64_to_user_ptr(kattr->test.data_out); int err = -EFAULT;
@@ -96,8 +110,35 @@ static int bpf_test_finish(const union bpf_attr *kattr, err = -ENOSPC; } - if (data_out && copy_to_user(data_out, data, copy_size)) - goto out; + if (data_out) { + int len = copy_size - bpf_test_get_buff_data_len(sinfo); + + if (copy_to_user(data_out, data, len)) + goto out; + + if (sinfo) { + int i, offset = len, data_len; + + for (i = 0; i < sinfo->nr_frags; i++) { + skb_frag_t *frag = &sinfo->frags[i]; + + if (offset >= copy_size) { + err = -ENOSPC; + break; + } + + data_len = min_t(int, copy_size - offset, + skb_frag_size(frag)); + if (copy_to_user(data_out + offset, + skb_frag_address(frag), + data_len)) + goto out; + + offset += data_len; + } + } + } + if (copy_to_user(&uattr->test.data_size_out, &size, sizeof(size))) goto out; if (copy_to_user(&uattr->test.retval, &retval, sizeof(retval)))
@@ -598,7 +639,8 @@ int bpf_prog_test_run_skb(struct bpf_prog *prog, const union bpf_attr *kattr, /* bpf program can never convert linear skb to non-linear */ if (WARN_ON_ONCE(skb_is_nonlinear(skb))) size = skb_headlen(skb); - ret = bpf_test_finish(kattr, uattr, skb->data, size, retval, duration); + ret = bpf_test_finish(kattr, uattr, skb->data, NULL, size, retval, + duration); if (!ret) ret = bpf_ctx_finish(kattr, uattr, ctx, sizeof(struct __sk_buff));
@@ -683,7 +725,9 @@ int bpf_prog_test_run_xdp(struct bpf_prog *prog, const union bpf_attr *kattr, if (xdp.data != data + headroom || xdp.data_end != xdp.data + size) size += xdp.data_end - xdp.data - data_len; - ret = bpf_test_finish(kattr, uattr, xdp.data, size, retval, duration); + ret = bpf_test_finish(kattr, uattr, xdp.data, sinfo, size, retval, + duration); + out: bpf_prog_change_xdp(prog, NULL); for (i = 0; i < sinfo->nr_frags; i++)
@@ -793,8 +837,8 @@ int bpf_prog_test_run_flow_dissector(struct bpf_prog *prog, do_div(time_spent, repeat); duration = time_spent > U32_MAX ? U32_MAX : (u32)time_spent; - ret = bpf_test_finish(kattr, uattr, &flow_keys, sizeof(flow_keys), - retval, duration); + ret = bpf_test_finish(kattr, uattr, &flow_keys, NULL, + sizeof(flow_keys), retval, duration); if (!ret) ret = bpf_ctx_finish(kattr, uattr, user_ctx, sizeof(struct bpf_flow_keys));
--
2.26.2